diff --git a/crates/weksa/src/context.rs b/crates/weksa/src/context.rs
index 28c43db..877c974 100644
--- a/crates/weksa/src/context.rs
+++ b/crates/weksa/src/context.rs
@@ -8,7 +8,9 @@
 //! consts in this module; every prompt also lists the inventory at the run's
 //! revision. A mint prompt is the editor's: it reads [`TrainItems`], an
 //! [`Inventory`] and an [`EditFeedback`] and nothing else, so no held-out text,
-//! key or per-item score can reach it.
+//! key or per-item score can reach it. A lowering prompt names the language it
+//! is said in on a language line; every language is named by its tag, none by a
+//! default.
 //!
 //! Item text may hold line breaks; the renderer indents every continuation line
 //! (`indented`), so item text cannot forge a `[key]` line or a paragraph.
@@ -25,7 +27,7 @@ use serde::Serialize;
 
 use crate::corpus::{CorpusItem, CorpusItemId};
 use crate::inventory::{Inventory, InventoryEntry, OptionLabel, ValueKind};
-use crate::lower::{EntityForms, LowerError, TARGET_LANGUAGE, entity};
+use crate::lower::{EntityForms, LowerError, entity};
 use crate::packet::{
     Context, Discourse, EntityId, Extension, Predication, Referent, Relation, Stance,
 };
@@ -37,7 +39,7 @@ use crate::validate::LoweringInput;
 /// The instructions a mint prompt starts with: the editor's whole brief. Fixed
 /// per run by `PROMPT_SOURCE_DIGEST`.
 pub const MINT_INSTRUCTIONS: &str = "\
-Propose one edit to the inventory below, so that the lines below can be encoded and lowered to English more faithfully.
+Propose one edit to the inventory below, so that the lines below can be encoded and lowered, each in its own language, more faithfully.
 Answer with one JSON object and nothing else: no code fence, no commentary.
 Shape: {\"add\": [{\"family\", \"gloss\", \"value_kind\", \"applies_to\"}], \"retire\": [ids]}; 1 to 8 changes in all, adds and retires together.
 - family: one of Concept, Frame, Role, Relation, SpeechAct, Feature, ReferentKind, Extension.
@@ -65,7 +67,7 @@ A feature is {feature, value}; value is {\"Grade\": 0 to 1000}, {\"Option\": lab
 /// The instructions a lowering prompt starts with: the lowerer's whole brief.
 /// Fixed per run by `PROMPT_SOURCE_DIGEST`.
 pub const LOWER_INSTRUCTIONS: &str = "\
-Say the packet below in English (en-US), as one utterance of its speaker: all of its meaning and nothing it does not carry.
+Say the packet below in the language on the language line, as one utterance of its speaker: all of its meaning and nothing it does not carry.
 Every id is the inventory's listed below and every feature value is as listed; a grade is permille, 0 to 1000. The stance is the speaker's felt affect and restraint: it shapes how the utterance is said, not what it says.
 A referent with an entity is named by one of that entity's forms on the entities line.
 Answer with one JSON object and nothing else: {\"text\": \"...\"}. No code fence, no commentary.";
@@ -81,14 +83,14 @@ Answer with one JSON object and nothing else: {\"text\": \"...\"}, the continuat
 /// reads; it cannot be built from a slice, and no accessor returns text or an
 /// item.
 ///
-/// ```
+/// ```no_run
 /// # let dir = tempfile::tempdir().unwrap();
 /// # let p = |n: &str| dir.path().join(n);
-/// # for n in ["c.cc", "i.cc", "e.cc"] { std::fs::write(p(n), [0x90]).unwrap(); }
 /// # let paths = weksa::run::RunPaths { corpus: &p("c.cc"), inventory: &p("i.cc"), entities: &p("e.cc") };
-/// # let run = weksa::run::RunStores::create(&p("run"), "t", paths, "m", "e", weksa::run::LowererReach::ToolLessRelay, weksa::corpus::ModelFamily::Unrecorded).unwrap();
+/// # let panel = ["en-US".to_string()];
+/// # let run = weksa::run::RunStores::create(&p("run"), "t", paths, "m", "e", weksa::run::LowererReach::ToolLessRelay, weksa::corpus::ModelFamily::Unrecorded, &panel).unwrap();
 /// let t = run.train().unwrap();
-/// assert!(t.is_empty());
+/// let _ = t.len();
 /// ```
 ///
 /// ```compile_fail
@@ -100,7 +102,7 @@ Answer with one JSON object and nothing else: {\"text\": \"...\"}, the continuat
 /// # let p = |n: &str| dir.path().join(n);
 /// # for n in ["c.cc", "i.cc", "e.cc"] { std::fs::write(p(n), [0x90]).unwrap(); }
 /// # let paths = weksa::run::RunPaths { corpus: &p("c.cc"), inventory: &p("i.cc"), entities: &p("e.cc") };
-/// # let run = weksa::run::RunStores::create(&p("run"), "t", paths, "m", "e", weksa::run::LowererReach::ToolLessRelay, weksa::corpus::ModelFamily::Unrecorded).unwrap();
+/// # let run = weksa::run::RunStores::create(&p("run"), "t", paths, "m", "e", weksa::run::LowererReach::ToolLessRelay, weksa::corpus::ModelFamily::Unrecorded, &["en-US".to_string()]).unwrap();
 /// let t = run.train().unwrap();
 /// let _u = t.clone();
 /// ```
@@ -111,7 +113,7 @@ Answer with one JSON object and nothing else: {\"text\": \"...\"}, the continuat
 /// # let p = |n: &str| dir.path().join(n);
 /// # for n in ["c.cc", "i.cc", "e.cc"] { std::fs::write(p(n), [0x90]).unwrap(); }
 /// # let paths = weksa::run::RunPaths { corpus: &p("c.cc"), inventory: &p("i.cc"), entities: &p("e.cc") };
-/// # let run = weksa::run::RunStores::create(&p("run"), "t", paths, "m", "e", weksa::run::LowererReach::ToolLessRelay, weksa::corpus::ModelFamily::Unrecorded).unwrap();
+/// # let run = weksa::run::RunStores::create(&p("run"), "t", paths, "m", "e", weksa::run::LowererReach::ToolLessRelay, weksa::corpus::ModelFamily::Unrecorded, &["en-US".to_string()]).unwrap();
 /// let t = run.train().unwrap();
 /// s(&t);
 /// ```
@@ -120,11 +122,14 @@ pub struct TrainItems {
 }
 
 impl TrainItems {
-    pub(crate) fn from_corpus(corpus: &CorpusStore) -> anyhow::Result<Self> {
+    /// The live Train items whose language is in `panel`.
+    pub(crate) fn from_corpus(corpus: &CorpusStore, panel: &[String]) -> anyhow::Result<Self> {
         let items = corpus
             .all()?
             .into_iter()
-            .filter(|item| SplitScheme::V1.live(item) == Some(Split::Train))
+            .filter(|item| {
+                SplitScheme::V1.live(item) == Some(Split::Train) && panel.contains(&item.language)
+            })
             .collect();
         Ok(Self { items })
     }
@@ -252,11 +257,13 @@ impl<'cp> EncoderOffer<'cp> {
 }
 
 /// What the editor is told of how its last edit fared: whether it was kept, and
-/// the held-out composite at the current inventory, rounded to the nearest
-/// [`LADDER_STEP`]. The head composite changes only when an edit is accepted and
-/// an accept needs a gain above one step, so a run releases at most
-/// `1 / LADDER_STEP` distinct values (Blum and Hardt 2015, the Ladder). Nothing
-/// else about the held-out split is a field.
+/// the held-out composite at the current inventory of each panel language,
+/// rounded to the nearest [`LADDER_STEP`]. The heads change only when an edit is
+/// accepted, and an accept raises the panel's composite sum by more than one
+/// step, so a run over `L` languages releases at most `1.5 * L / LADDER_STEP`
+/// changes of this line (Blum and Hardt 2015, the Ladder; ruling
+/// `weksa-lowering:ruling:panel-accept-sum-rule`). Nothing else about the
+/// held-out split is a field.
 ///
 /// ```
 /// let f = weksa::context::EditFeedback::none();
@@ -266,18 +273,18 @@ impl<'cp> EncoderOffer<'cp> {
 /// Its fields are private:
 ///
 /// ```compile_fail,E0451
-/// let _ = weksa::context::EditFeedback { last: None, head: None };
+/// let _ = weksa::context::EditFeedback { last: None, head: vec![] };
 /// ```
 ///
 /// and only the run builds one with a reading:
 ///
 /// ```compile_fail,E0624
-/// let _ = weksa::context::EditFeedback::new(Some(true), Some(0.5));
+/// let _ = weksa::context::EditFeedback::new(Some(true), vec![]);
 /// ```
-#[derive(Clone, Copy, Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct EditFeedback {
     last: Option<bool>,
-    head: Option<f64>,
+    head: Vec<(String, f64)>,
 }
 
 impl EditFeedback {
@@ -285,16 +292,20 @@ impl EditFeedback {
     pub fn none() -> Self {
         Self {
             last: None,
-            head: None,
+            head: Vec::new(),
         }
     }
 
-    /// `last`: whether the previous edit was accepted; `head`: the composite at
-    /// the current inventory, rounded here to the nearest [`LADDER_STEP`].
-    pub(crate) fn new(last: Option<bool>, head: Option<f64>) -> Self {
+    /// `last`: whether the previous edit was accepted; `head`: each panel
+    /// language's composite at the current inventory, in panel order, rounded
+    /// here to the nearest [`LADDER_STEP`].
+    pub(crate) fn new(last: Option<bool>, head: Vec<(String, f64)>) -> Self {
         Self {
             last,
-            head: head.map(|x| (x / LADDER_STEP).round() * LADDER_STEP),
+            head: head
+                .into_iter()
+                .map(|(tag, x)| (tag, (x / LADDER_STEP).round() * LADDER_STEP))
+                .collect(),
         }
     }
 
@@ -304,7 +315,15 @@ impl EditFeedback {
             Some(false) => "rejected",
             None => "none",
         };
-        let head = self.head.map_or("none".to_string(), |x| format!("{x:.3}"));
+        let head = if self.head.is_empty() {
+            "none".to_string()
+        } else {
+            self.head
+                .iter()
+                .map(|(tag, x)| format!("{tag} {x:.3}"))
+                .collect::<Vec<_>>()
+                .join(", ")
+        };
         format!("last edit: {last}; validation composite at head: {head}")
     }
 }
@@ -312,12 +331,12 @@ impl EditFeedback {
 /// Text for a model call, and the keys of the items it holds. The only
 /// constructors are [`Prompt::mint`], [`Prompt::encode`] and [`Prompt::lower`].
 ///
-/// ```
+/// ```no_run
 /// # let dir = tempfile::tempdir().unwrap();
 /// # let p = |n: &str| dir.path().join(n);
-/// # for n in ["c.cc", "i.cc", "e.cc"] { std::fs::write(p(n), [0x90]).unwrap(); }
 /// # let paths = weksa::run::RunPaths { corpus: &p("c.cc"), inventory: &p("i.cc"), entities: &p("e.cc") };
-/// # let run = weksa::run::RunStores::create(&p("run"), "t", paths, "m", "e", weksa::run::LowererReach::ToolLessRelay, weksa::corpus::ModelFamily::Unrecorded).unwrap();
+/// # let panel = ["en-US".to_string()];
+/// # let run = weksa::run::RunStores::create(&p("run"), "t", paths, "m", "e", weksa::run::LowererReach::ToolLessRelay, weksa::corpus::ModelFamily::Unrecorded, &panel).unwrap();
 /// let t = run.train().unwrap();
 /// let inv = run.inventory().inventory().unwrap();
 /// let feedback = weksa::context::EditFeedback::none();
@@ -335,7 +354,7 @@ impl EditFeedback {
 /// # let p = |n: &str| dir.path().join(n);
 /// # for n in ["c.cc", "i.cc", "e.cc"] { std::fs::write(p(n), [0x90]).unwrap(); }
 /// # let paths = weksa::run::RunPaths { corpus: &p("c.cc"), inventory: &p("i.cc"), entities: &p("e.cc") };
-/// # let run = weksa::run::RunStores::create(&p("run"), "t", paths, "m", "e", weksa::run::LowererReach::ToolLessRelay, weksa::corpus::ModelFamily::Unrecorded).unwrap();
+/// # let run = weksa::run::RunStores::create(&p("run"), "t", paths, "m", "e", weksa::run::LowererReach::ToolLessRelay, weksa::corpus::ModelFamily::Unrecorded, &["en-US".to_string()]).unwrap();
 /// let t = run.train().unwrap();
 /// let inv = run.inventory().inventory().unwrap();
 /// let feedback = weksa::context::EditFeedback::none();
@@ -348,7 +367,7 @@ impl EditFeedback {
 /// # let p = |n: &str| dir.path().join(n);
 /// # for n in ["c.cc", "i.cc", "e.cc"] { std::fs::write(p(n), [0x90]).unwrap(); }
 /// # let paths = weksa::run::RunPaths { corpus: &p("c.cc"), inventory: &p("i.cc"), entities: &p("e.cc") };
-/// # let run = weksa::run::RunStores::create(&p("run"), "t", paths, "m", "e", weksa::run::LowererReach::ToolLessRelay, weksa::corpus::ModelFamily::Unrecorded).unwrap();
+/// # let run = weksa::run::RunStores::create(&p("run"), "t", paths, "m", "e", weksa::run::LowererReach::ToolLessRelay, weksa::corpus::ModelFamily::Unrecorded, &["en-US".to_string()]).unwrap();
 /// let t = run.train().unwrap();
 /// let inv = run.inventory().inventory().unwrap();
 /// let feedback = weksa::context::EditFeedback::none();
@@ -502,17 +521,19 @@ impl Prompt {
         }
     }
 
-    /// [`LOWER_INSTRUCTIONS`], the meaning of `input` (no kind, constraints,
-    /// scene, speaker or group), the en-US forms of every entity its referents
-    /// cite, and the entries of `inventory` live at the view's revision. `item`
+    /// [`LOWER_INSTRUCTIONS`], the `language: <tag>` line, the meaning of
+    /// `input` (no kind, constraints, scene, speaker or group), the forms in
+    /// `language` of every entity its referents cite, and the entries of `inventory` live at the view's revision. `item`
     /// goes only to [`Prompt::item_keys`], never into the text. The view's
     /// speaker and group fields are never read; a speaker's entity id appears
     /// only when the encoder cites that entity on a referent, which is naming a
     /// cited entity like any other. A cited entity the port lacks, or one with
-    /// no en-US form, is an error and no prompt.
+    /// no form in `language`, is an error and no prompt. The caller chooses the
+    /// language; the view has none.
     pub fn lower(
         input: &LoweringInput,
         item: &CorpusItemId,
+        language: &str,
         inventory: &Inventory,
         entities: &dyn EntityForms,
     ) -> Result<Prompt, LowerError> {
@@ -520,7 +541,7 @@ impl Prompt {
         for id in input.referents().iter().filter_map(|r| r.entity.as_ref()) {
             let found = entity(entities, id)?;
             let named = found
-                .forms_in(TARGET_LANGUAGE)
+                .forms_in(language)
                 .filter(|f| !f.is_empty())
                 .ok_or_else(|| LowerError::NoForm { entity: id.clone() })?;
             forms.insert(id.as_str(), named.to_vec());
@@ -536,7 +557,7 @@ impl Prompt {
         };
         let rev = input.inventory_rev();
         let text = format!(
-            "{LOWER_INSTRUCTIONS}\n\npacket: {}\n\nentities: {}\n\ninventory rev:{rev}{}",
+            "{LOWER_INSTRUCTIONS}\n\nlanguage: {language}\n\npacket: {}\n\nentities: {}\n\ninventory rev:{rev}{}",
             serde_json::to_string(&meaning).expect("a meaning is plain data"),
             serde_json::to_string(&forms).expect("forms are plain data"),
             inventory_lines(inventory, rev)
@@ -583,34 +604,50 @@ mod tests {
 
     #[test]
     fn the_feedback_line_prints_exact_values() {
+        let en = |x: f64| vec![("en-US".to_string(), x)];
         let line = |last, head| EditFeedback::new(last, head).line();
         assert_eq!(
             EditFeedback::none().line(),
             "last edit: none; validation composite at head: none"
         );
         assert_eq!(
-            line(Some(true), Some(0.5)),
-            "last edit: accepted; validation composite at head: 0.500"
+            line(Some(true), en(0.5)),
+            "last edit: accepted; validation composite at head: en-US 0.500"
         );
         assert_eq!(
-            line(Some(false), Some(0.0)),
-            "last edit: rejected; validation composite at head: 0.000"
+            line(Some(false), en(0.0)),
+            "last edit: rejected; validation composite at head: en-US 0.000"
         );
-        assert_eq!(line(None, None), EditFeedback::none().line());
+        assert_eq!(line(None, vec![]), EditFeedback::none().line());
         // The head is rounded to the nearest step before it is printed.
         assert_eq!(
-            line(None, Some(0.5012)),
-            "last edit: none; validation composite at head: 0.500"
+            line(None, en(0.5012)),
+            "last edit: none; validation composite at head: en-US 0.500"
         );
         assert_eq!(
-            line(None, Some(0.5026)),
-            "last edit: none; validation composite at head: 0.505"
+            line(None, en(0.5026)),
+            "last edit: none; validation composite at head: en-US 0.505"
         );
         assert_eq!(
-            line(None, Some(0.9999)),
-            "last edit: none; validation composite at head: 1.000"
+            line(None, en(0.9999)),
+            "last edit: none; validation composite at head: en-US 1.000"
         );
-        assert_eq!(EditFeedback::new(None, Some(0.5026)).head, Some(0.505));
+        // One value per panel language, in the order given.
+        assert_eq!(
+            line(None, vec![("en-US".into(), 0.5026), ("ja-JP".into(), 0.41)]),
+            "last edit: none; validation composite at head: en-US 0.505, ja-JP 0.410"
+        );
+    }
+
+    #[test]
+    fn a_mint_prompt_over_no_train_items_is_the_brief_the_feedback_and_the_listing() {
+        let none = TrainItems { items: vec![] };
+        let prompt = Prompt::mint(&none, &Inventory::default(), 0, &EditFeedback::none());
+        assert_eq!(
+            prompt.text(),
+            format!("{MINT_INSTRUCTIONS}\n\nlast edit: none; validation composite at head: none\n\ninventory rev:0")
+        );
+        assert!(prompt.item_keys().is_empty());
     }
 
     #[test]
diff --git a/crates/weksa/src/lower.rs b/crates/weksa/src/lower.rs
index e8e1ea9..76f3158 100644
--- a/crates/weksa/src/lower.rs
+++ b/crates/weksa/src/lower.rs
@@ -43,8 +43,10 @@ use crate::phones::{Phone, PhoneInventory, SegmentError};
 use crate::store::EntityStore;
 use crate::validate::LoweringInput;
 
-/// The language tag this lowerer's entity forms are read under, spelled as an
-/// entity's `LanguageForms::language` and a corpus item's language are.
+/// The language tag of the template table and the phones: what `weksa lower`
+/// says in. The golf loop lowers each item in its own language and does not
+/// read this. Spelled as an entity's `LanguageForms::language` and a corpus
+/// item's language are.
 pub const TARGET_LANGUAGE: &str = "en-US";
 
 /// The lowerer's whole view of the entity store: one entity by id. Narrow so a
diff --git a/crates/weksa/src/main.rs b/crates/weksa/src/main.rs
index a92c010..8270565 100644
--- a/crates/weksa/src/main.rs
+++ b/crates/weksa/src/main.rs
@@ -99,6 +99,10 @@ enum LoopCommand {
         /// that family wrote. Defaults to unrecorded.
         #[arg(long, default_value = "unrecorded")]
         answerer_family: ModelFamilyArg,
+        /// The languages the run offers, reads and decides on: BCP 47 tags,
+        /// comma-separated. Every one needs a live Train and Validation item.
+        #[arg(long, value_delimiter = ',', required = true)]
+        panel: Vec<String>,
     },
     /// Run one round of the run at ROOT. The stores are read only from the
     /// run's record: the global --corpus, --inventory and --entities are not
@@ -329,7 +333,8 @@ struct AddArgs {
     /// NFC-normalized here; `--name` byte offsets index the normalized text.
     #[arg(long)]
     text: String,
-    #[arg(long, default_value = "en-US")]
+    /// The item's language, a BCP 47 tag; no language is the default.
+    #[arg(long)]
     language: String,
     /// An entity id.
     #[arg(long)]
@@ -765,6 +770,7 @@ fn main() -> Result<()> {
             embed_model,
             lowerer_reach,
             answerer_family,
+            panel,
         }) => {
             let run = RunStores::create(
                 &root,
@@ -778,6 +784,7 @@ fn main() -> Result<()> {
                 &embed_model,
                 lowerer_reach,
                 answerer_family.into(),
+                &panel,
             )?;
             println!("opened run:{}", run.record().label);
         }
@@ -821,12 +828,12 @@ fn main() -> Result<()> {
                     std::process::exit(3);
                 }
                 AblationOutcome::Read(readings) => {
-                    for (split, reading) in readings {
+                    for (language, split, reading) in readings {
                         let name = match split {
                             Split::Train => "train",
                             _ => "validation",
                         };
-                        println!("{name} {}", reading.line());
+                        println!("{language} {name} {}", reading.line());
                     }
                 }
             }
diff --git a/crates/weksa/src/run.rs b/crates/weksa/src/run.rs
index dbbf6ad..a1b879d 100644
--- a/crates/weksa/src/run.rs
+++ b/crates/weksa/src/run.rs
@@ -36,6 +36,7 @@ use cultcache_rs::{
 };
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
+use unicode_segmentation::UnicodeSegmentation;
 
 use crate::context::{EditFeedback, EncoderOffer, Prompt, TrainItems};
 use crate::corpus::{CorpusItem, CorpusItemId, ModelFamily, Source};
@@ -52,8 +53,8 @@ use crate::validate::LoweringInput;
 
 /// The digest of the prompt builder's source: `context.rs`, then `split.rs`,
 /// whose scheme and digest function decide which lines the prompt holds as
-/// Train and name every prompt, then `lower.rs`, whose `TARGET_LANGUAGE` and
-/// `EntityForms` port the lowering prompt reads, then `packet.rs`, whose serde
+/// Train and name every prompt, then `lower.rs`, whose `EntityForms` port and
+/// `entity()` the lowering prompt reads, then `packet.rs`, whose serde
 /// shapes the lowering prompt prints as the packet. Each file enters the digest
 /// behind its length, so the parts cannot be re-cut into other parts with the
 /// same digest. Any edit to any of them, comments included, ends a run; code
@@ -66,10 +67,12 @@ pub const PROMPT_SOURCE_DIGEST: u64 = fnv1a64_of(&[
 ]);
 
 /// The least composite gain an edit must show over item noise to be kept, and
-/// the grid the editor's one held-out number is rounded to. A run releases at
-/// most `1 / LADDER_STEP` = 200 distinct head composites (the Ladder, Blum and
-/// Hardt 2015), because the head changes only on an accept and an accept needs
-/// a gain above one step.
+/// the grid the editor's one held-out number is rounded to. Every accept raises
+/// the panel's composite sum by more than one step and a composite lies in
+/// -0.5 to 1, so a run over `L` languages accepts, and changes the released
+/// heads, at most `1.5 * L / LADDER_STEP` times (`300` for one language; the
+/// Ladder, Blum and Hardt 2015; ruling
+/// `weksa-lowering:ruling:panel-accept-sum-rule`, see [`decide_panel`]).
 pub const LADDER_STEP: f64 = 0.005;
 
 /// What a run pinned at open. Key `run:<label>`.
@@ -117,6 +120,11 @@ pub struct RunRecord {
     #[cultcache(key = 13, default)]
     #[schemars(default)]
     pub answerer_family: ModelFamily,
+    /// The languages the run offers, reads and decides on: BCP 47-form tags,
+    /// sorted, unique, at least one, set once at open. An item of any other
+    /// language is never offered, minted from, probed or scored.
+    #[cultcache(key = 14)]
+    pub panel: Vec<String>,
 }
 
 /// How a run's lowering prompts reach the model that answers them (rulings
@@ -200,6 +208,22 @@ pub struct RefusalCounts {
     pub lower: u32,
 }
 
+/// One panel language's readings in a round: the means over that language's
+/// items only (a refused item counts 0) and how many items lowered and scored.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct LanguageRound {
+    pub language: String,
+    pub train_mean: SplitMean,
+    /// Train items that lowered and scored; `train_mean` is over all of them.
+    pub train_scored: u32,
+    pub validation_mean: SplitMean,
+    /// Validation items that lowered and scored; `validation_mean` is over all
+    /// of them and counts a refused item as 0, so refusing a weak item cannot
+    /// raise it.
+    pub validation_scored: u32,
+    pub validation_refused: RefusalCounts,
+}
+
 /// One scored round. It holds no text and no Test reading: per-item rows for
 /// Train only, Validation only as means and refusal counts by stage. Only
 /// `run::round` builds one.
@@ -212,8 +236,7 @@ pub struct RefusalCounts {
 /// is the same literal in the unit test `a_round_record_literal_compiles_in_the_lib`.
 ///
 /// ```compile_fail,E0451
-/// use weksa::run::{RefusalCounts, RoundRecord};
-/// use weksa::score::SplitMean;
+/// use weksa::run::RoundRecord;
 /// fn f() -> RoundRecord {
 ///     RoundRecord {
 ///         n: 1,
@@ -226,16 +249,12 @@ pub struct RefusalCounts {
 ///         chrf_version: String::new(),
 ///         calls: vec![],
 ///         train: vec![],
-///         train_mean: SplitMean::default(),
-///         train_scored: 0,
-///         validation_mean: SplitMean::default(),
-///         validation_scored: 0,
-///         validation_refused: RefusalCounts::default(),
 ///         inventory_digest: String::new(),
 ///         cycle: None,
 ///         admit_rules: vec![],
 ///         parse_reasons: vec![],
 ///         own_family: 0,
+///         languages: vec![],
 ///     }
 /// }
 /// ```
@@ -265,21 +284,8 @@ pub struct RoundRecord {
     calls: Vec<Call>,
     #[cultcache(key = 10)]
     train: Vec<TrainRow>,
-    #[cultcache(key = 11)]
-    train_mean: SplitMean,
-    #[cultcache(key = 12)]
-    validation_mean: SplitMean,
-    #[cultcache(key = 13)]
-    validation_refused: RefusalCounts,
-    /// Train items that lowered and scored; `train_mean` is over all of them
-    /// and counts a refused item as 0.
-    #[cultcache(key = 14)]
-    train_scored: u32,
-    /// Validation items that lowered and scored; `validation_mean` is over all
-    /// of them and counts a refused item as 0, so refusing a weak item cannot
-    /// raise it.
-    #[cultcache(key = 15)]
-    validation_scored: u32,
+    // Keys 11 to 15 (the pooled means and counts) are retired and never reused:
+    // a run.cc from before does not open.
     /// 16 hex of the inventory file the round was scored under.
     #[cultcache(key = 16)]
     inventory_digest: String,
@@ -304,6 +310,10 @@ pub struct RoundRecord {
     #[cultcache(key = 20, default)]
     #[schemars(default)]
     own_family: u32,
+    /// One reading per panel language, in panel order. No pooled mean exists.
+    // Key 20 is `own_family`; the per-language readings take 21.
+    #[cultcache(key = 21)]
+    languages: Vec<LanguageRound>,
 }
 
 impl RoundRecord {
@@ -337,20 +347,12 @@ impl RoundRecord {
     pub fn train(&self) -> &[TrainRow] {
         &self.train
     }
-    pub fn train_mean(&self) -> &SplitMean {
-        &self.train_mean
+    /// The panel languages' readings, in panel order.
+    pub fn languages(&self) -> &[LanguageRound] {
+        &self.languages
     }
-    pub fn validation_mean(&self) -> &SplitMean {
-        &self.validation_mean
-    }
-    pub fn validation_refused(&self) -> RefusalCounts {
-        self.validation_refused
-    }
-    pub fn train_scored(&self) -> u32 {
-        self.train_scored
-    }
-    pub fn validation_scored(&self) -> u32 {
-        self.validation_scored
+    pub fn language(&self, tag: &str) -> Option<&LanguageRound> {
+        self.languages.iter().find(|l| l.language == tag)
     }
     pub fn inventory_digest(&self) -> &str {
         &self.inventory_digest
@@ -368,37 +370,38 @@ impl RoundRecord {
         self.own_family
     }
 
-    /// The round line, unlabelled: [`RunStores::round_line`] adds how the run was lowered. `n` is every item of the split,
-    /// `scored` those that lowered; a mean counts a refused item as 0.
+    /// The round line, unlabelled: [`RunStores::round_line`] adds how the run
+    /// was lowered. One segment per panel language; `n` is every item of the
+    /// split, `scored` those that lowered; a mean counts a refused item as 0.
     fn line(&self) -> String {
         let mean = |value: Option<f64>, places: usize| {
             value.map_or("none".to_string(), |v| format!("{v:.places$}"))
         };
-        let refused = self
-            .train
-            .iter()
-            .filter(|row| matches!(row.outcome, Outcome::Refused(_)))
-            .count();
-        let (t, v, x) = (
-            &self.train_mean,
-            &self.validation_mean,
-            self.validation_refused,
-        );
+        let segment = |l: &LanguageRound| {
+            let (t, v, x) = (&l.train_mean, &l.validation_mean, l.validation_refused);
+            let refused = t.count.saturating_sub(l.train_scored as usize);
+            format!(
+                "{} train n={} scored={} chrf={} meaning={} refused={refused} validation n={} scored={} chrf={} meaning={} refused parse={} admit={} lower={}",
+                l.language,
+                t.count,
+                l.train_scored,
+                mean(t.chrf, 2),
+                mean(t.meaning, 4),
+                v.count,
+                l.validation_scored,
+                mean(v.chrf, 2),
+                mean(v.meaning, 4),
+                x.parse,
+                x.admit,
+                x.lower,
+            )
+        };
+        let segments: Vec<String> = self.languages.iter().map(segment).collect();
         let line = format!(
-            "round {} rev {} train n={} scored={} chrf={} meaning={} refused={refused} validation n={} scored={} chrf={} meaning={} refused parse={} admit={} lower={}",
+            "round {} rev {} {}",
             self.n,
             self.inventory_rev,
-            t.count,
-            self.train_scored,
-            mean(t.chrf, 2),
-            mean(t.meaning, 4),
-            v.count,
-            self.validation_scored,
-            mean(v.chrf, 2),
-            mean(v.meaning, 4),
-            x.parse,
-            x.admit,
-            x.lower,
+            segments.join(" ")
         );
         let codes = |counts: &[RuleCount]| {
             counts
@@ -458,6 +461,9 @@ pub enum RunError {
     /// The round holds no answer to a lowering prompt the ablation rebuilt: the
     /// prompt's digest drifted or the head inventory moved since the round.
     Unrecorded,
+    /// The panel is empty, repeats or misspells a language, or names one with no
+    /// live Train or Validation item in the pinned corpus.
+    Panel,
 }
 
 impl fmt::Display for RunError {
@@ -479,6 +485,9 @@ impl fmt::Display for RunError {
             RunError::Embed => f.write_str("the embedder failed"),
             RunError::NoFloor => f.write_str("the run has no noise floor: record two rounds first"),
             RunError::NoValidation => f.write_str("a reading has no validation item"),
+            RunError::Panel => f.write_str(
+                "the panel is empty, repeats or misspells a language, or names one with no live Train or Validation item",
+            ),
         }
     }
 }
@@ -586,8 +595,11 @@ fn copy_new(from: &Path, to: &Path) -> Result<(), RunError> {
 }
 
 impl RunStores {
-    /// Pins the three stores at `root`, which must hold no run. A store file
-    /// that does not exist is `Io(NotFound)`.
+    /// Pins the three stores at `root`, which must hold no run, and the panel:
+    /// the languages the run offers, reads and decides on. A store file that
+    /// does not exist is `Io(NotFound)`; a bad panel is `Panel` and writes
+    /// nothing.
+    #[allow(clippy::too_many_arguments)]
     pub fn create(
         root: &Path,
         label: &str,
@@ -596,6 +608,7 @@ impl RunStores {
         embedder: &str,
         reach: LowererReach,
         answerer_family: ModelFamily,
+        panel: &[String],
     ) -> Result<Self, RunError> {
         Self::create_between(
             root,
@@ -605,6 +618,7 @@ impl RunStores {
             embedder,
             reach,
             answerer_family,
+            panel,
             || {},
         )
     }
@@ -612,7 +626,7 @@ impl RunStores {
     /// `create` with `between` run after the digests are taken and before the
     /// stores are opened: the seam that lets a test change a store in that window.
     #[doc(hidden)]
-    #[allow(clippy::too_many_arguments)] // `create`'s six plus the test seam
+    #[allow(clippy::too_many_arguments)] // `create`'s seven plus the test seam
     pub fn create_between(
         root: &Path,
         label: &str,
@@ -621,6 +635,7 @@ impl RunStores {
         embedder: &str,
         reach: LowererReach,
         answerer_family: ModelFamily,
+        panel: &[String],
         between: impl FnOnce(),
     ) -> Result<Self, RunError> {
         if !is_slug(label) {
@@ -632,6 +647,13 @@ impl RunStores {
         if !is_attestation(embedder) {
             return Err(RunError::Malformed("embedder"));
         }
+        let mut panel = panel.to_vec();
+        panel.sort();
+        // A tag no item carries (misspelt, wrong case, not a tag) is refused by
+        // `check_panel` once the corpus is open.
+        if panel.is_empty() || panel.windows(2).any(|w| w[0] == w[1]) {
+            return Err(RunError::Panel);
+        }
         let cache = run_cache(root)?;
         if one_run(&cache)?.is_some() {
             return Err(RunError::Exists);
@@ -650,6 +672,7 @@ impl RunStores {
             inventory_digest: String::new(),
             lowerer_reach: reach,
             answerer_family,
+            panel,
         };
         // The run works on its own copy; the caller's store is never opened again.
         let head = root.join(INVENTORY_FILE);
@@ -665,6 +688,7 @@ impl RunStores {
             };
             between();
             let mut run = Self::with(root, cache, record)?;
+            run.check_panel()?;
             // The stores were read between the digests: unless they still match
             // the pins, what was opened is not what was pinned. Nothing is
             // recorded for a run that did not pin.
@@ -724,6 +748,26 @@ impl RunStores {
         &self.record
     }
 
+    /// Every panel language holds a live Train and a live Validation item.
+    fn check_panel(&self) -> Result<(), RunError> {
+        let items = self.corpus.all().map_err(|_| RunError::Store)?;
+        let holds = |tag: &String, split: Split| {
+            items
+                .iter()
+                .any(|i| &i.language == tag && SplitScheme::V1.live(i) == Some(split))
+        };
+        if self
+            .record
+            .panel
+            .iter()
+            .all(|tag| holds(tag, Split::Train) && holds(tag, Split::Validation))
+        {
+            Ok(())
+        } else {
+            Err(RunError::Panel)
+        }
+    }
+
     /// `line` (a round or cycle summary) with how this run's lowerings were
     /// answered; a briefed-subagent run says its numbers are smoke-round only.
     pub fn labelled(&self, line: &str) -> String {
@@ -755,9 +799,9 @@ impl RunStores {
         &self.entities
     }
 
-    /// The live Train items of the pinned corpus.
+    /// The live Train items of the pinned corpus in a panel language.
     pub fn train(&self) -> anyhow::Result<TrainItems> {
-        TrainItems::from_corpus(&self.corpus)
+        TrainItems::from_corpus(&self.corpus, &self.record.panel)
     }
 
     /// The offer for `key`; the inner error is the gate's refusal. An absent
@@ -769,17 +813,20 @@ impl RunStores {
         let item = self
             .corpus
             .get(key)?
+            .filter(|item| self.record.panel.contains(&item.language))
             .ok_or_else(|| anyhow::anyhow!("no such item"))?;
         Ok(EncoderOffer::for_round(&item))
     }
 
-    /// The live Train and Validation offers, in key order. Items the gate
-    /// refuses are skipped and read no further.
+    /// The live Train and Validation offers in a panel language, in key order.
+    /// Items the gate refuses, and items of any other language, are skipped
+    /// and read no further.
     pub fn offers(&self) -> anyhow::Result<Vec<EncoderOffer<'static>>> {
         Ok(self
             .corpus
             .all()?
             .iter()
+            .filter(|item| self.record.panel.contains(&item.language))
             .filter_map(|item| EncoderOffer::for_round(item).ok())
             .collect())
     }
@@ -862,11 +909,19 @@ pub enum RoundOutcome {
 
 /// A recall reading (`lowering-recall-diagnostic`): how closely a fresh model
 /// completes each live Train and Validation item from its opening alone, chrF against the
-/// item's own second half. Recorded nowhere: the answers stay in `<root>/recall`.
-/// It is never a gate; a high reading says a round's scores on these items are
-/// recitation.
+/// item's own second half, one reading per panel language. Recorded nowhere:
+/// the answers stay in `<root>/recall`. It is never a gate; a high reading says
+/// a round's scores on these items are recitation.
 #[derive(Clone, Debug, PartialEq)]
 pub struct RecallReading {
+    /// In panel order.
+    pub languages: Vec<LanguageRecall>,
+}
+
+/// One panel language's recall reading.
+#[derive(Clone, Debug, PartialEq)]
+pub struct LanguageRecall {
+    pub language: String,
     /// Items probed, Train and Validation.
     pub n: u32,
     /// Items whose completion was a usable answer; a refused one counts 0.
@@ -876,10 +931,24 @@ pub struct RecallReading {
 
 impl RecallReading {
     pub fn line(&self) -> String {
-        format!(
-            "recall n={} answered={} chrf={:.2} (completion from the opening; unrelated English already scores chrf 14 to 20, so a reading near that floor is no recitation and one well above it is)",
-            self.n, self.answered, self.chrf
-        )
+        self.languages
+            .iter()
+            .map(|l| {
+                let segment = format!(
+                    "recall {} n={} answered={} chrf={:.2}",
+                    l.language, l.n, l.answered, l.chrf
+                );
+                // The one language whose unrelated-text floor was measured.
+                if l.language == "en-US" {
+                    format!(
+                        "{segment} (completion from the opening; unrelated English already scores chrf 14 to 20, so a reading near that floor is no recitation and one well above it is)"
+                    )
+                } else {
+                    segment
+                }
+            })
+            .collect::<Vec<_>>()
+            .join(" | ")
     }
 }
 
@@ -889,20 +958,27 @@ pub enum RecallOutcome {
     Read(RecallReading),
 }
 
-/// The opening and the rest of `text`, split between words at about the
-/// middle; `None` when it has fewer than four words.
+/// The opening and the rest of `text`, split at the Unicode word boundary
+/// (UAX #29) nearest the byte middle; `None` when it has fewer than four words.
+/// One rule for every script: a line written without spaces is probed like any
+/// other.
 fn recall_split(text: &str) -> Option<(String, String)> {
-    let words: Vec<&str> = text.split_whitespace().collect();
-    if words.len() < 4 {
+    if text.unicode_words().count() < 4 {
         return None;
     }
-    let (head, tail) = words.split_at(words.len() / 2);
-    Some((head.join(" "), tail.join(" ")))
+    let middle = text.len() / 2;
+    let at = text
+        .split_word_bound_indices()
+        .map(|(i, _)| i)
+        .filter(|&i| i > 0)
+        .min_by_key(|&i| i.abs_diff(middle))?;
+    let (head, tail) = text.split_at(at);
+    Some((head.trim().to_string(), tail.trim().to_string()))
 }
 
 impl RunStores {
-    /// Probes every live Train and Validation item of the pinned corpus once,
-    /// through `model`. A public-domain item names its work, author and
+    /// Probes every live Train and Validation item of the pinned corpus in a
+    /// panel language once, through `model`. A public-domain item names its work, author and
     /// translator; any other says `work: not published`.
     pub fn recall(&self, model: &mut dyn ModelPort) -> Result<RecallOutcome, RunError> {
         let store = |_| RunError::Store;
@@ -917,41 +993,60 @@ impl RunStores {
                 } => format!("work: {work}\nauthor: {author}\ntranslator: {translator}"),
                 _ => "work: not published".to_string(),
             };
-            if EncoderOffer::for_round(&item).is_err() {
+            if !self.record.panel.contains(&item.language)
+                || EncoderOffer::for_round(&item).is_err()
+            {
                 continue;
             }
             if let Some((opening, rest)) = recall_split(&item.text) {
                 let prompt = Prompt::recall(&item.id, &provenance, &opening);
-                probes.push((prompt, rest));
+                probes.push((item.language.clone(), prompt, rest));
             }
         }
         let mut unanswered = Vec::new();
         let mut scores = Vec::new();
-        for (prompt, rest) in &probes {
+        for (language, prompt, rest) in &probes {
             match model.answer(prompt) {
                 Ok(answer) => {
                     let text = LoweringDraft::parse(&answer)
                         .ok()
                         .filter(LoweringDraft::usable)
                         .map(|d| d.text);
-                    scores.push(text.map(|t| chrf(&t, rest)));
+                    scores.push((language, text.map(|t| chrf(&t, rest))));
                 }
                 Err(PortError::Unanswered) => unanswered.push(prompt.digest()),
-                Err(PortError::Io(ErrorKind::InvalidData)) => scores.push(None),
+                Err(PortError::Io(ErrorKind::InvalidData)) => scores.push((language, None)),
                 Err(PortError::Io(kind)) => return Err(RunError::Io(kind)),
             }
         }
         if !unanswered.is_empty() {
             return Ok(RecallOutcome::Unanswered { prompts: unanswered });
         }
-        let n = scores.len() as u32;
-        let answered = scores.iter().flatten().count() as u32;
-        let chrf = if n == 0 {
-            0.0
-        } else {
-            scores.iter().map(|s| s.unwrap_or(0.0)).sum::<f64>() / f64::from(n)
-        };
-        Ok(RecallOutcome::Read(RecallReading { n, answered, chrf }))
+        let languages = self
+            .record
+            .panel
+            .iter()
+            .map(|tag| {
+                let of: Vec<Option<f64>> = scores
+                    .iter()
+                    .filter(|(language, _)| *language == tag)
+                    .map(|(_, score)| *score)
+                    .collect();
+                let n = of.len() as u32;
+                let chrf = if n == 0 {
+                    0.0
+                } else {
+                    of.iter().map(|s| s.unwrap_or(0.0)).sum::<f64>() / f64::from(n)
+                };
+                LanguageRecall {
+                    language: tag.clone(),
+                    n,
+                    answered: of.iter().flatten().count() as u32,
+                    chrf,
+                }
+            })
+            .collect();
+        Ok(RecallOutcome::Read(RecallReading { languages }))
     }
 
     /// `<root>/recall`, where a recall's prompts and answers live.
@@ -1028,8 +1123,8 @@ impl AblationReading {
 #[derive(Debug)]
 pub enum AblationOutcome {
     Unanswered { prompts: Vec<String> },
-    /// Train then Validation.
-    Read(Vec<(Split, AblationReading)>),
+    /// Per panel language in panel order, Train then Validation.
+    Read(Vec<(String, Split, AblationReading)>),
 }
 
 /// What the port made of one lowering prompt.
@@ -1058,6 +1153,9 @@ fn mean(xs: impl Iterator<Item = f64>) -> Option<f64> {
 
 type Scored = (ItemScore, ItemScore);
 
+/// A panel language's live items of one split, each with its round packet.
+type HeldSplit = (String, Split, Vec<(CorpusItem, Packet)>);
+
 /// One item's reference text, recorded lowering, replay, and drop and permute
 /// lowerings.
 type Lowered = (String, String, String, [Option<String>; 2]);
@@ -1070,7 +1168,7 @@ impl RunStores {
     }
 
     /// A diagnostic like [`recall`](Self::recall), never a gate: for each live
-    /// Train and Validation packet of plain round `n`, asks the lowerer again
+    /// Train and Validation packet of plain round `n`, per panel language, asks the lowerer again
     /// (`model`, the replay), with the packet's stance emptied (drop) and with
     /// the next item's stance in its split (permute), and reads how far the
     /// lowering moves against the round's own answer (`recorded`). Test and
@@ -1111,16 +1209,20 @@ impl RunStores {
             .map_err(store)?
             .all()
             .map_err(store)?;
-        let mut splits: [(Split, Vec<(CorpusItem, Packet)>); 2] =
-            [(Split::Train, Vec::new()), (Split::Validation, Vec::new())];
+        let mut splits: Vec<HeldSplit> = Vec::new();
+        for tag in &self.record.panel {
+            for split in [Split::Train, Split::Validation] {
+                splits.push((tag.clone(), split, Vec::new()));
+            }
+        }
         for packet in round_packets {
             let item = self
                 .corpus
                 .get(packet.provenance.corpus_item.as_str())
                 .map_err(store)?
                 .ok_or(RunError::Store)?;
-            for (split, held) in &mut splits {
-                if SplitScheme::V1.live(&item) == Some(*split) {
+            for (language, split, held) in &mut splits {
+                if *language == item.language && SplitScheme::V1.live(&item) == Some(*split) {
                     held.push((item.clone(), packet.clone()));
                 }
             }
@@ -1130,8 +1232,8 @@ impl RunStores {
         let mut readings = Vec::new();
         // Texts per split: (item text, recorded, replay, [drop, permute]).
         let mut texts: Vec<Vec<Lowered>> = Vec::new();
-        let mut unusable = [0u32; 2];
-        for (at, (_, held)) in splits.iter_mut().enumerate() {
+        let mut unusable = vec![0u32; splits.len()];
+        for (at, (_, _, held)) in splits.iter_mut().enumerate() {
             held.sort_by(|a, b| a.0.id.as_str().cmp(b.0.id.as_str()));
             let mut rows = Vec::new();
             for (i, (item, packet)) in held.iter().enumerate() {
@@ -1140,7 +1242,7 @@ impl RunStores {
                     let view = stores[slot]
                         .admit(packet, &self.inventory, &self.corpus, &self.entities)
                         .map_err(|_| RunError::Store)?;
-                    Prompt::lower(&view, &packet_item, &inventory, &self.entities)
+                    Prompt::lower(&view, &packet_item, &item.language, &inventory, &self.entities)
                         .map_err(|_| RunError::Store)
                 };
                 let base = prompt_of(0, packet.clone())?;
@@ -1215,7 +1317,7 @@ impl RunStores {
         let mut pair = || -> Result<Scored, RunError> {
             Ok((scores.next().ok_or(RunError::Store)?, scores.next().ok_or(RunError::Store)?))
         };
-        for (at, ((split, _), rows)) in splits.iter().zip(&texts).enumerate() {
+        for (at, ((language, split, _), rows)) in splits.iter().zip(&texts).enumerate() {
             let mut replay: Vec<Scored> = Vec::new();
             let mut variants: [Vec<(Scored, Scored)>; 2] = [Vec::new(), Vec::new()];
             for (_, _, _, got) in rows {
@@ -1238,6 +1340,7 @@ impl RunStores {
                 ),
             };
             readings.push((
+                language.clone(),
                 *split,
                 AblationReading {
                     n: rows.len() as u32,
@@ -1418,7 +1521,10 @@ fn score_round<M: ModelPort, E: Embedder>(
     // port. Nothing is kept unless every one is answered.
     let mut unanswered = Vec::new();
     for (at, id, packet_key, view) in &admitted {
-        let Ok(prompt) = Prompt::lower(view, id, &inventory, &run.entities) else {
+        // Each item is lowered in its own language: the only reference the
+        // scorer has is the item's own text.
+        let language = &items[*at].language;
+        let Ok(prompt) = Prompt::lower(view, id, language, &inventory, &run.entities) else {
             fates[*at] = Fate::Refused(Stage::Lower, Some(packet_key.clone()));
             continue;
         };
@@ -1497,11 +1603,25 @@ fn score_round<M: ModelPort, E: Embedder>(
         .zip(&score_at)
         .map(|(item, score)| (item, score.clone().unwrap_or_else(|| nothing.clone())))
         .collect();
-    let means = aggregate(&scored);
 
     let mut train_rows = Vec::new();
-    let mut refused = RefusalCounts::default();
-    let (mut train_scored, mut validation_scored) = (0, 0);
+    let mut languages: Vec<LanguageRound> = Vec::new();
+    for tag in &run.record.panel {
+        let of: Vec<(&CorpusItem, ItemScore)> = scored
+            .iter()
+            .filter(|(item, _)| &item.language == tag)
+            .cloned()
+            .collect();
+        let means = aggregate(&of);
+        languages.push(LanguageRound {
+            language: tag.clone(),
+            train_mean: means.train,
+            train_scored: 0,
+            validation_mean: means.validation,
+            validation_scored: 0,
+            validation_refused: RefusalCounts::default(),
+        });
+    }
     for ((item, fate), score) in items.iter().zip(&fates).zip(&score_at) {
         let (outcome, packet) = match (fate, score) {
             (Fate::Lowered(_, key), Some(score)) => (
@@ -1514,20 +1634,24 @@ fn score_round<M: ModelPort, E: Embedder>(
             (Fate::Refused(stage, key), _) => (Outcome::Refused(*stage), key.clone()),
             (Fate::Lowered(..), None) => return Err(RunError::Store),
         };
+        let round = languages
+            .iter_mut()
+            .find(|l| l.language == item.language)
+            .ok_or(RunError::Store)?;
         match (SplitScheme::V1.live(item), fate) {
             (Some(Split::Train), fate) => {
-                train_scored += u32::from(matches!(fate, Fate::Lowered(..)));
+                round.train_scored += u32::from(matches!(fate, Fate::Lowered(..)));
                 train_rows.push(TrainRow {
                     item: item.id.clone(),
                     packet,
                     outcome,
                 });
             }
-            (Some(Split::Validation), Fate::Lowered(..)) => validation_scored += 1,
+            (Some(Split::Validation), Fate::Lowered(..)) => round.validation_scored += 1,
             (Some(Split::Validation), Fate::Refused(stage, _)) => match stage {
-                Stage::Parse => refused.parse += 1,
-                Stage::Admit => refused.admit += 1,
-                Stage::Lower => refused.lower += 1,
+                Stage::Parse => round.validation_refused.parse += 1,
+                Stage::Admit => round.validation_refused.admit += 1,
+                Stage::Lower => round.validation_refused.lower += 1,
             },
             _ => {}
         }
@@ -1554,11 +1678,6 @@ fn score_round<M: ModelPort, E: Embedder>(
         chrf_version: run.record.chrf_version.clone(),
         calls,
         train: train_rows,
-        train_mean: means.train,
-        validation_mean: means.validation,
-        validation_refused: refused,
-        train_scored,
-        validation_scored,
         inventory_digest: inventory_digest.to_string(),
         cycle,
         admit_rules: admit_rules
@@ -1570,6 +1689,7 @@ fn score_round<M: ModelPort, E: Embedder>(
             .map(|(rule, count)| RuleCount { rule, count })
             .collect(),
         own_family,
+        languages,
     };
     Ok(RoundOutcome::Recorded(record))
 }
@@ -1604,6 +1724,8 @@ impl Reading {
 pub enum Metric {
     Chrf,
     Meaning,
+    /// The composite fell, or a reading was not a finite number.
+    Composite,
 }
 
 /// Why an edit was rejected.
@@ -1638,15 +1760,37 @@ fn nano(x: f64) -> i64 {
     (x * 1e9).round() as i64
 }
 
-/// The accept rule. A metric that falls by more than its tolerance (the floor,
-/// at least one step) rejects; otherwise the composite must gain strictly more
-/// than [`threshold`]. Means count a refused Validation item as 0, so refusing a
-/// weak item cannot raise a reading. Differences are compared in billionths.
-pub fn decide(base: &Reading, candidate: &Reading, floor: &Reading) -> Verdict {
-    if nano(candidate.chrf - base.chrf) < -nano(floor.chrf.max(100.0 * LADDER_STEP)) {
-        Verdict::Rejected(Why::Regressed(Metric::Chrf))
+/// What regressed a language, or `None`: the one owner of the regression test,
+/// for [`decide`] and [`decide_panel`] alike. In order: a non-finite reading
+/// regresses the composite (fail closed: `nano` reads NaN as 0, which would
+/// otherwise read as unchanged); a metric that falls by more than its
+/// tolerance (the floor, at least one step) regresses that metric; the
+/// composite falling by more than max(its floor, one [`LADDER_STEP`])
+/// regresses the composite. Means count a refused Validation item as 0, so
+/// refusing a weak item cannot raise a reading. Differences are compared in
+/// billionths ([`nano`]), so a fall of exactly the tolerance is a tie.
+fn regression(base: &Reading, candidate: &Reading, floor: &Reading) -> Option<Metric> {
+    let finite = |r: &Reading| r.chrf.is_finite() && r.meaning.is_finite() && r.composite.is_finite();
+    if !(finite(base) && finite(candidate) && finite(floor)) {
+        Some(Metric::Composite)
+    } else if nano(candidate.chrf - base.chrf) < -nano(floor.chrf.max(100.0 * LADDER_STEP)) {
+        Some(Metric::Chrf)
     } else if nano(candidate.meaning - base.meaning) < -nano(floor.meaning.max(LADDER_STEP)) {
-        Verdict::Rejected(Why::Regressed(Metric::Meaning))
+        Some(Metric::Meaning)
+    } else if nano(candidate.composite - base.composite) < -nano(floor.composite.max(LADDER_STEP)) {
+        Some(Metric::Composite)
+    } else {
+        None
+    }
+}
+
+/// The accept rule for one language: [`regression`] rejects; otherwise the
+/// composite must gain strictly more than [`threshold`]. This is the gain test
+/// of a one-language panel and [`decide_panel`] calls it there, so a
+/// one-language panel is `decide` exactly.
+pub fn decide(base: &Reading, candidate: &Reading, floor: &Reading) -> Verdict {
+    if let Some(metric) = regression(base, candidate, floor) {
+        Verdict::Rejected(Why::Regressed(metric))
     } else if nano(candidate.composite - base.composite) > nano(threshold(floor)) {
         Verdict::Accepted
     } else {
@@ -1654,6 +1798,61 @@ pub fn decide(base: &Reading, candidate: &Reading, floor: &Reading) -> Verdict {
     }
 }
 
+/// The accept rule across the panel, over one `(base, candidate, floor)` row
+/// per panel language in panel order. One owner of each test: [`regression`]
+/// decides whether a language regressed (any regression rejects; the first in
+/// panel order names the metric), and the gain test is [`decide`]'s for one
+/// language and, for two or more, the panel's: the sum over languages of the
+/// composite deltas (billionths) must exceed one [`LADDER_STEP`]. A language
+/// may lose up to its own noise floor if the panel nets more than a step; the
+/// rule gives up strict Pareto non-regression, which on noisy per-language
+/// readings ratchets every base to a favourable draw and strangles the loop
+/// (the convergence test would then fire on noise). Wang, Lipton and Tsvetkov
+/// (EMNLP 2020) measure negative interference between languages sharing
+/// parameters, which the per-language regression test still bounds. The rule is
+/// ruling `weksa-lowering:ruling:panel-accept-sum-rule`.
+///
+/// Termination (the Ladder bound, Blum and Hardt 2015): every accept raises
+/// the sum of the panel's composites by more than [`LADDER_STEP`]. A composite
+/// is a mean of chrF as a fraction (0 to 1) and a cosine (-1 to 1), so lies in
+/// -0.5 to 1; the sum of `L` composites spans `1.5 * L`, and a run accepts at
+/// most `1.5 * L / LADDER_STEP` edits.
+pub fn decide_panel(rows: &[(Reading, Reading, Reading)]) -> Verdict {
+    if let [(base, candidate, floor)] = rows {
+        return decide(base, candidate, floor);
+    }
+    if let Some(metric) = rows
+        .iter()
+        .find_map(|(base, candidate, floor)| regression(base, candidate, floor))
+    {
+        return Verdict::Rejected(Why::Regressed(metric));
+    }
+    let net: i64 = rows
+        .iter()
+        .map(|(base, candidate, _)| nano(candidate.composite - base.composite))
+        .sum();
+    if net > nano(LADDER_STEP) {
+        Verdict::Accepted
+    } else {
+        Verdict::Rejected(Why::NoGain)
+    }
+}
+
+/// One panel language's row of a cycle: the head's Validation reading, the
+/// candidate's (none when the edit never reached a round), the language's
+/// measured floor and the threshold derived from it. The threshold decides only
+/// in a one-language panel ([`decide`]); with two or more languages it is
+/// recorded beside the floor and the accept is the sum rule of
+/// [`decide_panel`].
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct PanelReading {
+    pub language: String,
+    pub base: Reading,
+    pub candidate: Option<Reading>,
+    pub floor: Reading,
+    pub threshold: f64,
+}
+
 /// One closed edit-accept cycle: digests and numbers, no text. Key
 /// `run:<label>:cycle:<k>`. Only [`cycle`] builds one.
 ///
@@ -1665,9 +1864,8 @@ pub fn decide(base: &Reading, candidate: &Reading, floor: &Reading) -> Verdict {
 /// the same literal in the unit test `a_decision_literal_compiles_in_the_lib`.
 ///
 /// ```compile_fail,E0451
-/// use weksa::run::{Call, Decision, Reading, Verdict};
+/// use weksa::run::{Call, Decision, Verdict};
 /// fn f() -> Decision {
-///     let r = Reading { chrf: 0.0, meaning: 0.0, composite: 0.0 };
 ///     Decision {
 ///         k: 1,
 ///         base_round: 1,
@@ -1678,10 +1876,7 @@ pub fn decide(base: &Reading, candidate: &Reading, floor: &Reading) -> Verdict {
 ///         candidate_rev: None,
 ///         candidate_inventory_digest: None,
 ///         candidate_round: None,
-///         base: r,
-///         candidate: None,
-///         floor: r,
-///         threshold: 0.0,
+///         panel: vec![],
 ///         verdict: Verdict::Accepted,
 ///     }
 /// }
@@ -1710,16 +1905,12 @@ pub struct Decision {
     candidate_inventory_digest: Option<String>,
     #[cultcache(key = 8)]
     candidate_round: Option<u32>,
-    #[cultcache(key = 9)]
-    base: Reading,
-    #[cultcache(key = 10)]
-    candidate: Option<Reading>,
-    #[cultcache(key = 11)]
-    floor: Reading,
-    #[cultcache(key = 12)]
-    threshold: f64,
+    // Keys 9 to 12 (the pooled readings) are retired and never reused.
     #[cultcache(key = 13)]
     verdict: Verdict,
+    /// One row per panel language, in panel order.
+    #[cultcache(key = 14)]
+    panel: Vec<PanelReading>,
 }
 
 impl Decision {
@@ -1750,17 +1941,8 @@ impl Decision {
     pub fn candidate_round(&self) -> Option<u32> {
         self.candidate_round
     }
-    pub fn base(&self) -> &Reading {
-        &self.base
-    }
-    pub fn candidate(&self) -> Option<&Reading> {
-        self.candidate.as_ref()
-    }
-    pub fn floor(&self) -> &Reading {
-        &self.floor
-    }
-    pub fn threshold(&self) -> f64 {
-        self.threshold
+    pub fn panel(&self) -> &[PanelReading] {
+        &self.panel
     }
     pub fn verdict(&self) -> Verdict {
         self.verdict
@@ -1771,9 +1953,6 @@ impl Decision {
         let candidate_rev = self
             .candidate_rev
             .map_or("none".to_string(), |n| n.to_string());
-        let candidate = self
-            .candidate
-            .map_or("none".to_string(), |c| format!("{:.4}", c.composite));
         let verdict = match self.verdict {
             Verdict::Accepted => "accepted".to_string(),
             Verdict::Rejected(why) => format!(
@@ -1784,12 +1963,28 @@ impl Decision {
                     Why::NoGain => "no-gain",
                     Why::Regressed(Metric::Chrf) => "regressed-chrf",
                     Why::Regressed(Metric::Meaning) => "regressed-meaning",
+                    Why::Regressed(Metric::Composite) => "regressed-composite",
                 }
             ),
         };
+        let rows: Vec<String> = self
+            .panel
+            .iter()
+            .map(|p| {
+                let candidate = p
+                    .candidate
+                    .map_or("none".to_string(), |c| format!("{:.4}", c.composite));
+                format!(
+                    "{} base={:.4} candidate={candidate} floor={:.4} threshold={:.4}",
+                    p.language, p.base.composite, p.floor.composite, p.threshold
+                )
+            })
+            .collect();
         format!(
-            "cycle {} rev {}->{candidate_rev} base={:.4} candidate={candidate} floor={:.4} threshold={:.4} {verdict}",
-            self.k, self.base_rev, self.base.composite, self.floor.composite, self.threshold
+            "cycle {} rev {}->{candidate_rev} {} {verdict}",
+            self.k,
+            self.base_rev,
+            rows.join(" ")
         )
     }
 }
@@ -1805,30 +2000,60 @@ pub enum CycleOutcome {
     Decided(Decision),
 }
 
-/// The spread of the Validation reading between rounds 1 and 2: two independent
-/// encodings under the run's first inventory and one spec, measured once per run.
-fn floor_of(rounds: &[RoundRecord], record: &RunRecord) -> Result<Reading, RunError> {
-    let replicate = |n: u32| {
+/// The spread of each panel language's Validation reading between rounds 1 and
+/// 2: two independent encodings under the run's first inventory and one spec,
+/// measured once per run, in panel order.
+fn floor_of(
+    rounds: &[RoundRecord],
+    record: &RunRecord,
+) -> Result<Vec<(String, Reading)>, RunError> {
+    let replicate = |n: u32, tag: &str| {
         let round = rounds
             .iter()
             .find(|r| {
                 r.n == n && r.cycle.is_none() && r.inventory_digest == record.inventory_digest
             })
             .ok_or(RunError::NoFloor)?;
-        Reading::of(&round.validation_mean).ok_or(RunError::NoValidation)
+        let language = round.language(tag).ok_or(RunError::NoValidation)?;
+        Reading::of(&language.validation_mean).ok_or(RunError::NoValidation)
     };
-    let (a, b) = (replicate(1)?, replicate(2)?);
-    Ok(Reading {
-        chrf: (a.chrf - b.chrf).abs(),
-        meaning: (a.meaning - b.meaning).abs(),
-        composite: (a.composite - b.composite).abs(),
-    })
+    record
+        .panel
+        .iter()
+        .map(|tag| {
+            let (a, b) = (replicate(1, tag)?, replicate(2, tag)?);
+            Ok((
+                tag.clone(),
+                Reading {
+                    chrf: (a.chrf - b.chrf).abs(),
+                    meaning: (a.meaning - b.meaning).abs(),
+                    composite: (a.composite - b.composite).abs(),
+                },
+            ))
+        })
+        .collect()
+}
+
+/// Each panel language's Validation reading in `round`, in panel order.
+fn readings_of(
+    round: &RoundRecord,
+    record: &RunRecord,
+) -> Result<Vec<(String, Reading)>, RunError> {
+    record
+        .panel
+        .iter()
+        .map(|tag| {
+            let language = round.language(tag).ok_or(RunError::NoValidation)?;
+            let reading = Reading::of(&language.validation_mean).ok_or(RunError::NoValidation)?;
+            Ok((tag.clone(), reading))
+        })
+        .collect()
 }
 
 /// One edit-accept cycle. The editor is asked for one inventory edit from a
 /// prompt built over Train items, the head inventory and an [`EditFeedback`];
 /// the edit is admitted as a candidate revision in `<root>/cycle-<k>/inventory.cc`;
-/// a candidate round scores it; [`decide`] accepts or rejects on Validation
+/// a candidate round scores it; [`decide_panel`] accepts or rejects on Validation
 /// against the head's establishing round. Accepting is one write: the candidate
 /// round and the decision go into `run.cc` in one batch, and the decision names
 /// the new head. While any prompt is unanswered, or the candidate round fails,
@@ -1841,13 +2066,13 @@ pub fn cycle<M: ModelPort, E: Embedder>(
     let store = |_| RunError::Store;
     check_drift(run, model, scorer)?;
     let rounds = run.rounds().map_err(store)?;
-    let floor = floor_of(&rounds, &run.record)?;
+    let floors = floor_of(&rounds, &run.record)?;
     let (head_path, head_digest, base_round) = run.head()?;
     let base = rounds
         .iter()
         .find(|r| r.n == base_round)
         .ok_or(RunError::Store)?;
-    let base = Reading::of(&base.validation_mean).ok_or(RunError::NoValidation)?;
+    let bases = readings_of(base, &run.record)?;
     let decisions = run.decisions().map_err(store)?;
     let k = decisions.len() as u32 + 1;
     let dir = run.next_cycle_dir().map_err(store)?;
@@ -1856,7 +2081,10 @@ pub fn cycle<M: ModelPort, E: Embedder>(
 
     let feedback = EditFeedback::new(
         decisions.last().map(|d| d.verdict == Verdict::Accepted),
-        Some(base.composite),
+        bases
+            .iter()
+            .map(|(tag, reading)| (tag.clone(), reading.composite))
+            .collect(),
     );
     let train = run.train().map_err(store)?;
     let prompt = Prompt::mint(&train, &inventory, base_rev, &feedback);
@@ -1884,11 +2112,18 @@ pub fn cycle<M: ModelPort, E: Embedder>(
         candidate_rev: None,
         candidate_inventory_digest: None,
         candidate_round: None,
-        base,
-        candidate: None,
-        floor,
-        threshold: threshold(&floor),
         verdict,
+        panel: bases
+            .iter()
+            .zip(&floors)
+            .map(|((language, base), (_, floor))| PanelReading {
+                language: language.clone(),
+                base: *base,
+                candidate: None,
+                floor: *floor,
+                threshold: threshold(floor),
+            })
+            .collect(),
     };
     let decision_key = format!("run:{}:cycle:{k}", run.record.label);
     // A rejection leaves no candidate inventory behind, whichever attempt built it.
@@ -1933,15 +2168,23 @@ pub fn cycle<M: ModelPort, E: Embedder>(
         RoundOutcome::Unanswered { prompts } => return Ok(CycleOutcome::Unanswered { prompts }),
         RoundOutcome::Recorded(record) => record,
     };
-    let candidate = Reading::of(&record.validation_mean).ok_or(RunError::NoValidation)?;
-    let verdict = decide(&base, &candidate, &floor);
-    let decided = Decision {
+    let candidates = readings_of(&record, &run.record)?;
+    let rows: Vec<(Reading, Reading, Reading)> = bases
+        .iter()
+        .zip(&candidates)
+        .zip(&floors)
+        .map(|(((_, base), (_, candidate)), (_, floor))| (*base, *candidate, *floor))
+        .collect();
+    let verdict = decide_panel(&rows);
+    let mut decided = Decision {
         candidate_rev: Some(candidate_rev),
         candidate_inventory_digest: Some(candidate_digest),
         candidate_round: Some(record.n),
-        candidate: Some(candidate),
         ..blank(verdict)
     };
+    for (row, (_, candidate)) in decided.panel.iter_mut().zip(&candidates) {
+        row.candidate = Some(*candidate);
+    }
     let staged = vec![
         run.cache
             .prepare_entry_named(
@@ -1995,16 +2238,12 @@ mod tests {
             chrf_version: String::new(),
             calls: vec![],
             train: vec![],
-            train_mean: SplitMean::default(),
-            train_scored: 0,
-            validation_mean: SplitMean::default(),
-            validation_scored: 0,
-            validation_refused: RefusalCounts::default(),
             inventory_digest: String::new(),
             cycle: None,
             admit_rules: vec![],
             parse_reasons: vec![],
             own_family: 0,
+            languages: vec![],
         };
         assert_eq!(r.n(), 1);
     }
@@ -2012,11 +2251,6 @@ mod tests {
     /// The twin of the `Decision` literal in its compile_fail doctest.
     #[test]
     fn a_decision_literal_compiles_in_the_lib() {
-        let r = Reading {
-            chrf: 0.0,
-            meaning: 0.0,
-            composite: 0.0,
-        };
         let d = Decision {
             k: 1,
             base_round: 1,
@@ -2030,11 +2264,8 @@ mod tests {
             candidate_rev: None,
             candidate_inventory_digest: None,
             candidate_round: None,
-            base: r,
-            candidate: None,
-            floor: r,
-            threshold: 0.0,
             verdict: Verdict::Accepted,
+            panel: vec![],
         };
         assert_eq!(d.k(), 1);
     }
@@ -2140,7 +2371,33 @@ mod tests {
         assert_eq!(decide(&base, &gain(0.504), &zero), rejected(Why::NoGain));
         assert_eq!(decide(&base, &gain(0.506), &zero), Verdict::Accepted);
         assert_eq!(decide(&base, &gain(0.5), &zero), rejected(Why::NoGain));
-        assert_eq!(decide(&base, &gain(0.4), &zero), rejected(Why::NoGain));
+        // The composite may fall by its tolerance, max(floor.composite, one
+        // step): a fall of exactly that is a tie, a billionth past it regresses.
+        // (49.75 and 0.4975 keep the metrics inside theirs.)
+        let composite = rejected(Why::Regressed(Metric::Composite));
+        let fall = |c| reading(50.0, 0.5, c);
+        assert_eq!(decide(&base, &fall(0.4), &zero), composite);
+        assert_eq!(decide(&base, &fall(0.5 - LADDER_STEP), &zero), rejected(Why::NoGain), "a tie");
+        assert_eq!(decide(&base, &fall(0.5 - LADDER_STEP - 6e-10), &zero), composite, "rounds to nearest");
+        assert_eq!(decide(&base, &fall(0.5 - LADDER_STEP - 4e-10), &zero), rejected(Why::NoGain), "under half a billionth");
+        assert_eq!(decide(&base, &fall(0.5 - LADDER_STEP - 4e-9), &zero), composite, "a billionth grid, not a coarser one");
+        // A composite floor widens the tolerance, and only the composite's: a
+        // wide meaning floor does not.
+        let wide = reading(0.0, 0.0, 0.1);
+        assert_eq!(decide(&base, &fall(0.45), &wide), rejected(Why::NoGain));
+        assert_eq!(decide(&base, &fall(0.39), &wide), composite);
+        let wide_meaning = reading(0.0, 0.4, 0.0);
+        assert_eq!(decide(&base, &fall(0.45), &wide_meaning), composite);
+        // Each metric inside its own tolerance, the composite past its own.
+        assert_eq!(decide(&base, &reading(49.6, 0.496, 0.4), &zero), composite);
+        // Fail closed: NaN and infinity read as a regression, never as unchanged.
+        for bad in [f64::NAN, f64::INFINITY, f64::NEG_INFINITY] {
+            assert_eq!(decide(&base, &reading(bad, 0.5, 0.6), &zero), composite);
+            assert_eq!(decide(&base, &reading(50.0, bad, 0.6), &zero), composite);
+            assert_eq!(decide(&base, &reading(50.0, 0.5, bad), &zero), composite);
+            assert_eq!(decide(&reading(50.0, 0.5, bad), &gain(0.6), &zero), composite);
+            assert_eq!(decide(&base, &gain(0.6), &reading(0.0, 0.0, bad)), composite);
+        }
         // A floor above the step sets the threshold: a gain equal to it is no gain.
         let floor = reading(0.0, 0.0, 0.25);
         assert_eq!(decide(&base, &gain(0.75), &floor), rejected(Why::NoGain));
@@ -2148,6 +2405,229 @@ mod tests {
         assert_eq!(decide(&base, &gain(0.506), &floor), rejected(Why::NoGain));
     }
 
+    #[test]
+    fn decide_panel_table() {
+        let zero = reading(0.0, 0.0, 0.0);
+        let base = reading(50.0, 0.5, 0.5);
+        let rejected = Verdict::Rejected;
+        let gained = reading(50.0, 0.5, 0.6);
+        let regressed = reading(40.0, 0.5, 0.45);
+        let flat = base;
+        // One language gains, one is flat: accepted.
+        assert_eq!(
+            decide_panel(&[(base, gained, zero), (base, flat, zero)]),
+            Verdict::Accepted
+        );
+        // One gains, one regresses chrF past its floor: rejected, whichever is first.
+        for rows in [
+            [(base, gained, zero), (base, regressed, zero)],
+            [(base, regressed, zero), (base, gained, zero)],
+        ] {
+            assert_eq!(decide_panel(&rows), rejected(Why::Regressed(Metric::Chrf)));
+        }
+        // The first regression in panel order names the metric.
+        let meaning_down = reading(50.0, 0.4, 0.45);
+        assert_eq!(
+            decide_panel(&[(base, meaning_down, zero), (base, regressed, zero)]),
+            rejected(Why::Regressed(Metric::Meaning))
+        );
+        // Neither gaining: no gain.
+        assert_eq!(
+            decide_panel(&[(base, flat, zero), (base, flat, zero)]),
+            rejected(Why::NoGain)
+        );
+        // A big gain cannot buy a regression past a language's tolerance.
+        let sag = reading(50.0, 0.5, 0.4);
+        assert_eq!(
+            decide_panel(&[(base, reading(60.0, 0.9, 0.9), zero), (base, sag, zero)]),
+            rejected(Why::Regressed(Metric::Composite))
+        );
+        // It can buy a fall inside the language's own floor: the panel nets
+        // more than a step (strict Pareto is given up).
+        let small_fall = reading(50.0, 0.5, 0.497);
+        assert_eq!(
+            decide_panel(&[(base, gained, zero), (base, small_fall, zero)]),
+            Verdict::Accepted
+        );
+        // But not when the net is a step or less, on the billionth grid.
+        let net = |gain: f64| {
+            decide_panel(&[(base, reading(50.0, 0.5, 0.5 + gain), zero), (base, flat, zero)])
+        };
+        assert_eq!(net(LADDER_STEP), rejected(Why::NoGain), "a step is a tie");
+        assert_eq!(net(LADDER_STEP + 4e-10), rejected(Why::NoGain));
+        assert_eq!(net(LADDER_STEP + 6e-10), Verdict::Accepted);
+        assert_eq!(net(LADDER_STEP + 2e-9), Verdict::Accepted);
+        // Liveness: no language need pass its own threshold. Two languages each
+        // gaining 0.6 of a step at zero floor accept; so does one gaining two
+        // steps under a 0.02 floor (its own threshold) with the others flat; so
+        // does a gain with another language falling inside its own floor.
+        let each = 0.6 * LADDER_STEP;
+        assert_eq!(
+            decide_panel(&[
+                (base, reading(50.0, 0.5, 0.5 + each), zero),
+                (base, reading(50.0, 0.5, 0.5 + each), zero)
+            ]),
+            Verdict::Accepted
+        );
+        let big_floor = reading(0.0, 0.0, 0.02);
+        assert_eq!(
+            decide_panel(&[(base, reading(50.0, 0.5, 0.5 + 2.0 * LADDER_STEP), big_floor), (base, flat, big_floor)]),
+            Verdict::Accepted
+        );
+        let own_floor = reading(0.0, 0.0, 0.004);
+        assert_eq!(
+            decide_panel(&[
+                (base, reading(50.0, 0.5, 0.51), reading(0.0, 0.0, 0.03)),
+                (base, reading(50.0, 0.5, 0.497), own_floor)
+            ]),
+            Verdict::Accepted,
+            "a fall inside the language's floor, net 0.007"
+        );
+        // The same fall with the net exactly a step rejects.
+        assert_eq!(
+            decide_panel(&[
+                (base, reading(50.0, 0.5, 0.508), reading(0.0, 0.0, 0.03)),
+                (base, reading(50.0, 0.5, 0.497), own_floor)
+            ]),
+            rejected(Why::NoGain)
+        );
+        // The sum is over the deltas, with each language's fall counted.
+        assert_eq!(
+            decide_panel(&[(base, reading(50.0, 0.5, 0.504), zero), (base, small_fall, zero)]),
+            rejected(Why::NoGain)
+        );
+        // A one-language panel is decide() exactly, gain test included.
+        for candidate in [gained, regressed, flat, meaning_down, sag, small_fall, reading(50.0, 0.5, 0.504), reading(50.0, 0.5, 0.506), reading(50.0, 0.5, f64::NAN)] {
+            for floor in [zero, reading(1.0, 0.01, 0.02)] {
+                assert_eq!(
+                    decide_panel(&[(base, candidate, floor)]),
+                    decide(&base, &candidate, &floor)
+                );
+            }
+        }
+    }
+
+    /// One panel row per language: (base, candidate, floor), metrics held
+    /// inside every tolerance so only the composite moves.
+    fn rows(bases: &[f64], moves: &[f64], floor: f64) -> Vec<(Reading, Reading, Reading)> {
+        bases
+            .iter()
+            .zip(moves)
+            .map(|(b, d)| {
+                (
+                    reading(50.0, 0.5, *b),
+                    reading(50.0, 0.5, b + d),
+                    reading(0.0, 0.0, floor),
+                )
+            })
+            .collect()
+    }
+
+    /// The most edits a run accepts: each raises the sum of composites by more
+    /// than a step, and `L` composites span `1.5 * L` (-0.5 to 1).
+    fn bound(languages: usize) -> usize {
+        (1.5 * languages as f64 / LADDER_STEP) as usize
+    }
+
+    /// Soul's cycling cases: edits that raise one language and lower the others
+    /// inside their tolerances used to be accepted forever. The nets are zero
+    /// (and so are the accepts), always under the bound.
+    #[test]
+    fn a_rotation_of_gains_and_small_falls_is_bounded() {
+        // Three languages: each edit raises one by 0.0075, lowers two by 0.00375.
+        let mut head = [0.5, 0.5, 0.5];
+        let mut accepted = 0;
+        for k in 0..300 {
+            let mut step = [-0.00375; 3];
+            step[k % 3] = 0.0075;
+            if decide_panel(&rows(&head, &step, 0.0)) == Verdict::Accepted {
+                accepted += 1;
+                for (h, d) in head.iter_mut().zip(step) {
+                    *h += d;
+                }
+            }
+        }
+        assert!(accepted <= bound(3));
+        assert_eq!(accepted, 0, "the net is zero");
+        // Two languages: a gain of the step plus 2e-9 against a fall of the step.
+        let t = LADDER_STEP;
+        let head = [0.5, 0.5];
+        let mut accepted = 0;
+        for k in 0..2000 {
+            let mut step = [-t, -t];
+            step[k % 2] = t + 2e-9;
+            if decide_panel(&rows(&head, &step, 0.0)) == Verdict::Accepted {
+                accepted += 1;
+            }
+        }
+        assert!(accepted <= bound(2));
+        assert_eq!(accepted, 0, "the net is 2e-9, under the step");
+    }
+
+    /// Over a random walk of proposed edits a run accepts at most
+    /// `1.5 * L / LADDER_STEP`, and every accept raises the panel's composite
+    /// sum by more than a step.
+    #[test]
+    fn accepts_per_run_stay_inside_the_ladder_bound() {
+        let mut state = 0x9e37_79b9_7f4a_7c15_u64;
+        let mut next = move || {
+            state ^= state << 13;
+            state ^= state >> 7;
+            state ^= state << 17;
+            (state >> 11) as f64 / (1u64 << 53) as f64
+        };
+        for languages in [1usize, 2, 3, 5] {
+            // Heads anywhere in the composite's range, -0.5 to 1.
+            let mut head: Vec<f64> = (0..languages).map(|_| -0.5 + 1.5 * next()).collect();
+            let floor = 0.006 * next();
+            let mut accepted = 0usize;
+            for _ in 0..50_000 {
+                let step: Vec<f64> = head
+                    .iter()
+                    .map(|h| (h + (next() - 0.3) * 0.02).clamp(-0.5, 1.0) - h)
+                    .collect();
+                if decide_panel(&rows(&head, &step, floor)) == Verdict::Accepted {
+                    accepted += 1;
+                    let net: f64 = step.iter().sum();
+                    assert!(net > LADDER_STEP - 1e-9, "an accept netted {net}");
+                    for (h, d) in head.iter_mut().zip(&step) {
+                        *h += d;
+                    }
+                }
+            }
+            assert!(accepted <= bound(languages), "{languages}: {accepted} > {}", bound(languages));
+            assert!(accepted > 0, "the walk accepts something ({languages} languages)");
+        }
+    }
+
+    #[test]
+    fn a_composite_regression_prints_its_name() {
+        let r = reading(50.0, 0.5, 0.5);
+        let d = Decision {
+            k: 1,
+            base_round: 1,
+            base_rev: 3,
+            base_inventory_digest: String::new(),
+            edit: Call { prompt: String::new(), items: vec![] },
+            edit_answer_digest: None,
+            candidate_rev: Some(4),
+            candidate_inventory_digest: None,
+            candidate_round: None,
+            verdict: Verdict::Rejected(Why::Regressed(Metric::Composite)),
+            panel: vec![PanelReading {
+                language: "en-US".into(),
+                base: r,
+                candidate: Some(reading(50.0, 0.5, 0.4)),
+                floor: reading(0.0, 0.0, 0.0),
+                threshold: LADDER_STEP,
+            }],
+        };
+        assert_eq!(
+            d.line(),
+            "cycle 1 rev 3->4 en-US base=0.5000 candidate=0.4000 floor=0.0000 threshold=0.0050 rejected regressed-composite"
+        );
+    }
+
     #[test]
     fn a_gain_of_exactly_one_step_is_no_gain_on_every_baseline_of_the_grid() {
         let zero = reading(0.0, 0.0, 0.0);
@@ -2209,20 +2689,23 @@ mod tests {
             chrf_version: String::new(),
             calls: vec![],
             train: vec![],
-            train_mean: SplitMean::default(),
-            train_scored: 0,
-            validation_mean: SplitMean {
-                count: 2,
-                chrf: Some(chrf),
-                meaning: Some(meaning),
-            },
-            validation_scored: 2,
-            validation_refused: RefusalCounts::default(),
             inventory_digest: digest.to_string(),
             cycle: None,
             admit_rules: vec![],
             parse_reasons: vec![],
             own_family: 0,
+            languages: vec![LanguageRound {
+                language: "en-US".into(),
+                train_mean: SplitMean::default(),
+                train_scored: 0,
+                validation_mean: SplitMean {
+                    count: 2,
+                    chrf: Some(chrf),
+                    meaning: Some(meaning),
+                },
+                validation_scored: 2,
+                validation_refused: RefusalCounts::default(),
+            }],
         }
     }
 
@@ -2241,6 +2724,7 @@ mod tests {
             inventory_digest: digest.to_string(),
             lowerer_reach: LowererReach::ToolLessRelay,
             answerer_family: ModelFamily::Unrecorded,
+            panel: vec!["en-US".into()],
         }
     }
 
@@ -2251,7 +2735,9 @@ mod tests {
     fn the_floor_is_the_spread_of_each_field_of_the_two_replicates() {
         let record = record_of("d1");
         let rounds = [replicate(1, "d1", 60.0, 0.5), replicate(2, "d1", 50.0, 0.7)];
-        let floor = floor_of(&rounds, &record).unwrap();
+        let floors = floor_of(&rounds, &record).unwrap();
+        assert_eq!(floors.len(), 1);
+        let floor = floors[0].1;
         // composites 0.55 and 0.6.
         assert_eq!(floor.chrf, 10.0);
         assert!((floor.meaning - 0.2).abs() < 1e-12);
@@ -2274,7 +2760,7 @@ mod tests {
             replicate(2, "d1", 50.0, 0.7),
             replicate(1, "d1", 60.0, 0.5),
         ];
-        assert_eq!(floor_of(&rounds, &record).unwrap(), floor);
+        assert_eq!(floor_of(&rounds, &record).unwrap(), floors);
         assert_eq!(
             floor_of(&rounds[..3], &record).err(),
             Some(RunError::NoFloor)
@@ -2442,6 +2928,7 @@ mod tests {
                 "bag",
                 crate::run::LowererReach::ToolLessRelay,
                 ModelFamily::Unrecorded,
+                &["en-US".to_string()],
             )
             .unwrap();
             let mut model = fake();
diff --git a/crates/weksa/src/score/words.rs b/crates/weksa/src/score/words.rs
index 4909ee9..9e2ffb4 100644
--- a/crates/weksa/src/score/words.rs
+++ b/crates/weksa/src/score/words.rs
@@ -13,8 +13,10 @@
 //! word, never one word per character: per-character words would make every
 //! honest single-word gloss share bigrams with a held-out sentence, which is
 //! the leak signature. A change between such a run and any other script also
-//! ends a word. A leak in these scripts shows at n = 1 and in chrF; a
-//! dictionary segmenter is the ja-JP panel's to add.
+//! ends a word. The n >= 2 coverage signature is therefore blind on these
+//! scripts: a leak there shows at n = 1 and in max pairwise chrF, which is
+//! character n-grams and script-blind. A dictionary segmenter is follow-up
+//! `ja-word-segmenter`.
 
 use caseless::default_case_fold_str;
 use unicode_normalization::UnicodeNormalization;
diff --git a/crates/weksa/tests/cli.rs b/crates/weksa/tests/cli.rs
index f5562cd..5f75500 100644
--- a/crates/weksa/tests/cli.rs
+++ b/crates/weksa/tests/cli.rs
@@ -47,7 +47,7 @@ fn out(o: &Output) -> String {
     String::from_utf8_lossy(&o.stdout).into_owned() + &String::from_utf8_lossy(&o.stderr)
 }
 
-const ADD: [&str; 14] = [
+const ADD: [&str; 16] = [
     "corpus",
     "add",
     "--slug",
@@ -62,6 +62,8 @@ const ADD: [&str; 14] = [
     "2026-10-29",
     "--source",
     "cast-authored",
+    "--language",
+    "en-US",
 ];
 
 #[test]
@@ -149,6 +151,8 @@ fn model_written_and_public_domain_sources_name_their_provenance() {
     let base = [
         "corpus",
         "add",
+        "--language",
+        "en-US",
         "--slug",
         "x",
         "--speaker",
@@ -375,6 +379,8 @@ fn entity_put_and_name_spans() {
             &[
                 "corpus",
                 "add",
+                "--language",
+                "en-US",
                 "--slug",
                 "kay",
                 "--text",
@@ -547,6 +553,8 @@ fn add_with(dir: &std::path::Path, source: &str, extra: &[&str]) -> Output {
     let mut args = vec![
         "corpus",
         "add",
+        "--language",
+        "en-US",
         "--slug",
         "nibu",
         "--text",
@@ -903,6 +911,8 @@ fn proof_packet_lowers_and_the_lowering_scores_against_items() {
         &[
             "corpus",
             "add",
+            "--language",
+            "en-US",
             "--slug",
             "nibu",
             "--text",
@@ -1062,7 +1072,7 @@ fn cli_errors_never_echo_identifiers() {
     let p = d.path();
     cast_entities(p, &["nibu"]);
     let add = |extra: &[&str]| -> Vec<String> {
-        ["corpus", "add", "--admitted-on", "2026-10-29"]
+        ["corpus", "add", "--language", "en-US", "--admitted-on", "2026-10-29"]
             .into_iter()
             .chain(extra.iter().copied())
             .map(String::from)
@@ -1344,6 +1354,8 @@ fn loop_open_and_unanswered_round() {
                 "smoke",
                 "--answerer",
                 "fake-model",
+                "--panel",
+                "en-US",
                 "--lowerer-reach",
                 "tool-less-relay",
                 "--answerer-family",
@@ -1397,7 +1409,7 @@ fn loop_open_and_unanswered_round() {
     assert!(second.status.success(), "{}", out(&second));
     assert_eq!(
         out(&second),
-        "round 1 rev 3 train n=1 scored=0 chrf=0.00 meaning=0.0000 refused=1 validation n=2 scored=0 chrf=0.00 meaning=0.0000 refused parse=2 admit=0 lower=0 parse-reasons=syntaxx3 lowering=tool-less-relay\n"
+        "round 1 rev 3 en-US train n=1 scored=0 chrf=0.00 meaning=0.0000 refused=1 validation n=2 scored=0 chrf=0.00 meaning=0.0000 refused parse=2 admit=0 lower=0 parse-reasons=syntaxx3 lowering=tool-less-relay\n"
     );
 
     // The global store flags are not read by loop round: a drifted store is refused.
@@ -1424,6 +1436,8 @@ fn open_dao_run(d: &std::path::Path) {
             "smoke",
             "--answerer",
             "fake-model",
+            "--panel",
+            "en-US",
             "--lowerer-reach",
             "tool-less-relay",
         ],
@@ -1441,6 +1455,8 @@ fn pinned_family(d: &std::path::Path, root: &str, flag: &[&str]) -> weksa::corpu
         "fam",
         "--answerer",
         "fake-model",
+        "--panel",
+        "en-US",
         "--lowerer-reach",
         "tool-less-relay",
     ];
@@ -1526,7 +1542,7 @@ fn loop_cycle_asks_then_decides() {
     assert!(done.status.success(), "{}", out(&done));
     assert_eq!(
         out(&done),
-        "cycle 1 rev 3->none base=0.0000 candidate=none floor=0.0000 threshold=0.0050 rejected edit-parse lowering=tool-less-relay\n"
+        "cycle 1 rev 3->none en-US base=0.0000 candidate=none floor=0.0000 threshold=0.0050 rejected edit-parse lowering=tool-less-relay\n"
     );
 
     // The next cycle asks afresh in its own directory.
@@ -1565,6 +1581,8 @@ fn loop_errors_echo_no_input() {
             "CANARYLABEL",
             "--answerer",
             "m",
+            "--panel",
+            "en-US",
             "--lowerer-reach",
             "tool-less-relay",
         ],
@@ -1576,6 +1594,8 @@ fn loop_errors_echo_no_input() {
             "ok",
             "--answerer",
             "CANARY\n",
+            "--panel",
+            "en-US",
             "--lowerer-reach",
             "tool-less-relay",
         ],
@@ -1597,6 +1617,8 @@ fn loop_errors_echo_no_input() {
             "ok",
             "--answerer",
             "m",
+            "--panel",
+            "en-US",
             "--lowerer-reach",
             "tool-less-relay",
         ])
@@ -1610,7 +1632,7 @@ fn loop_errors_echo_no_input() {
 fn loop_open_requires_the_lowerer_reach_and_pins_it() {
     let d = tempfile::tempdir().unwrap();
     dao_stores(d.path());
-    let base = ["loop", "open", "canaryroot", "--label", "smoke", "--answerer", "m"];
+    let base = ["loop", "open", "canaryroot", "--label", "smoke", "--answerer", "m", "--panel", "en-US"];
     // No default: the record says how lowerings are answered, or there is no run.
     let o = weksa(d.path(), &base);
     assert!(!o.status.success());
@@ -1698,7 +1720,7 @@ fn loop_ablate_waits_then_prints_one_line_per_split() {
     let text = out(&second);
     assert_eq!(
         text,
-        "train ablation n=1 unusable=0 replay chrf=100.00 meaning=1.000 | drop n=1 chrf=100.00 meaning=1.000 moved=0 ref_gain_chrf=0.00 ref_gain_meaning=0.000 | permute n=0 chrf=none meaning=none moved=0 ref_gain_chrf=none ref_gain_meaning=none\nvalidation ablation n=2 unusable=0 replay chrf=100.00 meaning=1.000 | drop n=2 chrf=100.00 meaning=1.000 moved=0 ref_gain_chrf=0.00 ref_gain_meaning=0.000 | permute n=2 chrf=100.00 meaning=1.000 moved=0 ref_gain_chrf=0.00 ref_gain_meaning=0.000\n"
+        "en-US train ablation n=1 unusable=0 replay chrf=100.00 meaning=1.000 | drop n=1 chrf=100.00 meaning=1.000 moved=0 ref_gain_chrf=0.00 ref_gain_meaning=0.000 | permute n=0 chrf=none meaning=none moved=0 ref_gain_chrf=none ref_gain_meaning=none\nen-US validation ablation n=2 unusable=0 replay chrf=100.00 meaning=1.000 | drop n=2 chrf=100.00 meaning=1.000 moved=0 ref_gain_chrf=0.00 ref_gain_meaning=0.000 | permute n=2 chrf=100.00 meaning=1.000 moved=0 ref_gain_chrf=0.00 ref_gain_meaning=0.000\n"
     );
     for leaked in ["item:", "packet:", "highest excellence", "canaryroot"] {
         assert!(!text.contains(leaked), "{text}");
@@ -1720,3 +1742,24 @@ fn loop_ablate_without_the_rounds_answers_says_so() {
     assert!(text.contains("holds no answer") && text.contains("head inventory"), "{text}");
     assert!(!text.contains("would not read"), "{text}");
 }
+
+#[test]
+fn panel_and_language_are_required() {
+    let d = tempfile::tempdir().unwrap();
+    dao_stores(d.path());
+    // No panel: a run says what it reads, or there is no run.
+    let o = weksa(
+        d.path(),
+        &[
+            "loop", "open", "canaryroot", "--label", "smoke", "--answerer", "m",
+            "--lowerer-reach", "tool-less-relay",
+        ],
+    );
+    assert!(!o.status.success());
+    assert!(out(&o).contains("--panel"), "{}", out(&o));
+    assert!(!d.path().join("canaryroot/run.cc").exists());
+    // No language: no language is the unmarked one.
+    let o = weksa(d.path(), &ADD[..ADD.len() - 2]);
+    assert!(!o.status.success());
+    assert!(out(&o).contains("--language"), "{}", out(&o));
+}
diff --git a/crates/weksa/tests/common/mod.rs b/crates/weksa/tests/common/mod.rs
index 73c8456..b7b7c7e 100644
--- a/crates/weksa/tests/common/mod.rs
+++ b/crates/weksa/tests/common/mod.rs
@@ -116,12 +116,30 @@ pub fn entities_in(dir: &std::path::Path) -> EntityStore {
 
 /// A run over the stores `world()` and `corpus()` keep in `dir`: `c.cc`,
 /// `i.cc` and `entities.cc`. Read at the call, so create it after the items.
+/// The run's en-US panel needs a live Train and a live Validation item: a
+/// corpus short of one gets `item:panel:<n>` added, and no other item.
 pub fn run_over(dir: &std::path::Path) -> weksa::run::RunStores {
     for name in ["c.cc", "i.cc", "entities.cc"] {
         if !dir.join(name).exists() {
             std::fs::write(dir.join(name), [0x90]).unwrap();
         }
     }
+    let entities = entities_in(dir);
+    let mut corpus = CorpusStore::open(&dir.join("c.cc")).unwrap();
+    for (n, split) in [(1, weksa::Split::Train), (2, weksa::Split::Validation)] {
+        let held = corpus
+            .all()
+            .unwrap()
+            .iter()
+            .any(|i| SplitScheme::V1.live(i) == Some(split));
+        if !held {
+            let group = group_in_bucket(if n == 1 { 10 } else { 50 });
+            let key = format!("item:panel:{n}");
+            let text = format!("Panel fixture line {n}.");
+            corpus.add(item_in(&key, &text, &group, cast()), &entities).unwrap();
+        }
+    }
+    drop(corpus);
     weksa::run::RunStores::create(
         &dir.join("run"),
         "t",
@@ -134,6 +152,7 @@ pub fn run_over(dir: &std::path::Path) -> weksa::run::RunStores {
         "bag",
         weksa::run::LowererReach::ToolLessRelay,
         weksa::corpus::ModelFamily::Unrecorded,
+        &["en-US".to_string()],
     )
     .unwrap()
 }
@@ -219,6 +238,10 @@ pub fn world() -> World {
         end: 4,
     }];
     corpus.add(first, &entities).unwrap();
+    // A run's panel needs a live Validation item as well as a Train one.
+    let validation = group_in_bucket(50);
+    let second = item_in("item:panel:1", "Nibu says watch the ladder.", &validation, cast());
+    corpus.add(second, &entities).unwrap();
     let mut inventory = InventoryStore::open(&dir.path().join("i.cc")).unwrap();
     let (rev1, entries) = seed();
     inventory.admit_revision(rev1, entries).unwrap();
diff --git a/crates/weksa/tests/context.rs b/crates/weksa/tests/context.rs
index b908dcb..0103149 100644
--- a/crates/weksa/tests/context.rs
+++ b/crates/weksa/tests/context.rs
@@ -110,16 +110,6 @@ fn train_items_are_in_key_order() {
         ["item:a:1", "item:m:1", "item:z:1"]
     );
     assert_eq!((t.len(), t.is_empty()), (3, false));
-    let dir = tempfile::tempdir().unwrap();
-    let empty = run_over(dir.path());
-    let none = empty.train().unwrap();
-    assert_eq!((none.len(), none.is_empty()), (0, true));
-    let (inv, fb) = (empty.inventory().inventory().unwrap(), EditFeedback::none());
-    assert_eq!(
-        Prompt::mint(&none, &inv, 0, &fb).text(),
-        format!("{MINT}\n\nlast edit: none; validation composite at head: none\n\ninventory rev:0")
-    );
-    assert!(Prompt::mint(&none, &inv, 0, &fb).item_keys().is_empty());
 }
 
 #[test]
@@ -606,13 +596,28 @@ mod lowering {
         }
     }
 
+    /// The language line carries the tag the caller passes; no instruction
+    /// names a language.
+    #[test]
+    fn lower_prompt_names_its_language() {
+        let (view, inv, entities, item) = dao(2);
+        for tag in ["en-US", "ja-JP", "pt-BR"] {
+            let prompt = Prompt::lower(&view, &item, tag, &inv, &entities).unwrap();
+            let want = format!("{LOWER}\n\nlanguage: {tag}\n\npacket: ");
+            assert!(prompt.text().starts_with(&want), "{tag}");
+        }
+        for brief in [LOWER, weksa::context::MINT_INSTRUCTIONS] {
+            assert!(!brief.contains("English") && !brief.contains("en-US"));
+        }
+    }
+
     #[test]
     fn lower_prompt_text_is_pinned() {
         let (view, inv, entities, item) = dao(2);
-        let prompt = Prompt::lower(&view, &item, &inv, &entities).unwrap();
+        let prompt = Prompt::lower(&view, &item, "en-US", &inv, &entities).unwrap();
         let (head, listing) = prompt.text().split_once("inventory rev:3\n").unwrap();
         let expected = format!(
-            "{LOWER}\n\npacket: {}\n\nentities: {{}}\n\n",
+            "{LOWER}\n\nlanguage: en-US\n\npacket: {}\n\nentities: {{}}\n\n",
             concat!(
                 r#"{"context":{"setting":null,"medium":null,"participants":[],"audience":[]},"#,
                 r#""discourse":{"speech_act":"speech_act:1","addressee":null,"addressee_consent":null,"features":[]},"#,
@@ -628,7 +633,7 @@ mod lowering {
         assert!(listing.contains("\nfeature:18: "));
         // The brief says what the spec says it must.
         for needed in [
-            "en-US",
+            "the language on the language line",
             "all of its meaning and nothing it does not carry",
             "a grade is permille, 0 to 1000",
             "felt affect and restraint",
@@ -671,7 +676,7 @@ mod lowering {
             let mut packet = packets().remove(2);
             packet.stance = stance.clone();
             let view = admitted(packet, &store, "daodejing/corpus.cc", &entities);
-            let prompt = Prompt::lower(&view, &item, &inv, &entities).unwrap();
+            let prompt = Prompt::lower(&view, &item, "en-US", &inv, &entities).unwrap();
             (stance, prompt)
         };
         let three = [prompt_of(own), prompt_of(angry), prompt_of(Stance::default())];
@@ -708,7 +713,7 @@ mod lowering {
             ("sa-Latn", &["Nibuwa"]),
             ("en-US", &["Nibu", "Nibu's"]),
         ])]);
-        let prompt = Prompt::lower(&view, &item, &cast.inventory().unwrap(), &held).unwrap();
+        let prompt = Prompt::lower(&view, &item, "en-US", &cast.inventory().unwrap(), &held).unwrap();
         assert!(
             prompt
                 .text()
@@ -738,7 +743,7 @@ mod lowering {
             ),
             (Held(vec![]), LowerError::UnknownEntity { entity: id }),
         ] {
-            assert_eq!(Prompt::lower(&view, &item, &inv, &held).err(), Some(want));
+            assert_eq!(Prompt::lower(&view, &item, "en-US", &inv, &held).err(), Some(want));
         }
     }
 }
diff --git a/crates/weksa/tests/golf_loop.rs b/crates/weksa/tests/golf_loop.rs
index 4a1c7ee..73f1df2 100644
--- a/crates/weksa/tests/golf_loop.rs
+++ b/crates/weksa/tests/golf_loop.rs
@@ -51,6 +51,7 @@ fn a_run_pins_its_stores_and_refuses_drift() {
             "bag",
             weksa::run::LowererReach::ToolLessRelay,
             ModelFamily::Unrecorded,
+            &["en-US".to_string()],
         )
     };
 
@@ -154,6 +155,7 @@ fn a_run_works_on_its_own_copy_of_the_inventory() {
         "bag",
         weksa::run::LowererReach::ToolLessRelay,
         ModelFamily::Unrecorded,
+        &["en-US".to_string()],
     )
     .unwrap();
 
@@ -231,6 +233,7 @@ fn create_refuses_a_root_that_holds_an_inventory_and_never_truncates_it() {
             "bag",
             weksa::run::LowererReach::ToolLessRelay,
             ModelFamily::Unrecorded,
+            &["en-US".to_string()],
         )
     };
 
@@ -278,6 +281,7 @@ fn a_create_that_fails_leaves_no_inventory_and_the_retry_succeeds() {
             "bag",
             weksa::run::LowererReach::ToolLessRelay,
             ModelFamily::Unrecorded,
+            &["en-US".to_string()],
         )
     };
     // A directory opens for reading and fails mid-copy, after the destination exists.
@@ -398,6 +402,7 @@ fn a_store_changed_between_its_digest_and_its_open_is_drift() {
             "bag",
             weksa::run::LowererReach::ToolLessRelay,
             ModelFamily::Unrecorded,
+            &["en-US".to_string()],
             || more(&mut w)
         )
         .err(),
@@ -415,6 +420,7 @@ fn a_store_changed_between_its_digest_and_its_open_is_drift() {
         "bag",
         weksa::run::LowererReach::ToolLessRelay,
         ModelFamily::Unrecorded,
+        &["en-US".to_string()],
     )
     .unwrap();
 }
@@ -447,6 +453,7 @@ fn window(
         "bag",
         weksa::run::LowererReach::ToolLessRelay,
         ModelFamily::Unrecorded,
+        &["en-US".to_string()],
         || change(&mut w, &root),
     )
     .err();
@@ -841,6 +848,12 @@ fn dao() -> Dao {
 /// A Dao run whose stores `edit` (given the corpus and entity paths) changed
 /// before the run pinned them.
 fn dao_over(edit: impl FnOnce(&Path, &Path)) -> Dao {
+    dao_panel(edit, &["en-US"])
+}
+
+/// `dao_over` with the run opened on `panel`.
+fn dao_panel(edit: impl FnOnce(&Path, &Path), panel: &[&str]) -> Dao {
+    let panel: Vec<String> = panel.iter().map(|t| t.to_string()).collect();
     let src = Path::new(env!("CARGO_MANIFEST_DIR")).join("../../data/daodejing");
     let dir = tempfile::tempdir().unwrap();
     let copy = |from: &str, to: &str| {
@@ -866,6 +879,7 @@ fn dao_over(edit: impl FnOnce(&Path, &Path)) -> Dao {
         "bag",
         weksa::run::LowererReach::ToolLessRelay,
         ModelFamily::Unrecorded,
+        &panel,
     )
     .unwrap();
     Dao {
@@ -923,15 +937,15 @@ fn round_over_the_dao_stores_scores_train_and_validation() {
     };
     assert_eq!(two_dp(chrf), 44.18);
     assert!(meaning.is_some());
-    assert_eq!((r.train_mean().count, r.train_mean().chrf), (1, Some(chrf)));
+    assert_eq!((r.language("en-US").unwrap().train_mean.count, r.language("en-US").unwrap().train_mean.chrf), (1, Some(chrf)));
 
     // Validation: means and refusal counts only.
-    let v = r.validation_mean();
+    let v = &r.language("en-US").unwrap().validation_mean;
     assert_eq!(v.count, 2);
     assert!((v.chrf.unwrap() - 78.56).abs() < 0.01, "{:?}", v.chrf);
     assert!(v.meaning.is_some());
-    assert_eq!(r.validation_refused(), Default::default());
-    assert_eq!((r.train_scored(), r.validation_scored()), (1, 2));
+    assert_eq!(r.language("en-US").unwrap().validation_refused, Default::default());
+    assert_eq!((r.language("en-US").unwrap().train_scored, r.language("en-US").unwrap().validation_scored), (1, 2));
 
     // The record carries the run's pins.
     assert_eq!(r.prompt_digest(), pinned.prompt_digest);
@@ -1041,7 +1055,7 @@ fn lowering_prompts(dao: &Dao, inventory: &InventoryStore) -> Vec<(String, Promp
             let view = store
                 .admit(packet, inventory, &corpus, dao.run.entities())
                 .unwrap();
-            let prompt = Prompt::lower(&view, &key, &inv, dao.run.entities()).unwrap();
+            let prompt = Prompt::lower(&view, &key, "en-US", &inv, dao.run.entities()).unwrap();
             (key.to_string(), prompt)
         })
         .collect()
@@ -1139,7 +1153,7 @@ fn unanswered_round_writes_nothing() {
     let mut files = AnswerFiles::new(dao.run.next_round_dir().unwrap(), "fake-model".into());
     let r = recorded(round(&mut dao.run, &mut files, &Scorer::new(Bag)).unwrap());
     assert_eq!((r.n(), r.calls().len()), (1, 6));
-    assert_eq!(two_dp(r.train_mean().chrf.unwrap()), 44.18);
+    assert_eq!(two_dp(r.language("en-US").unwrap().train_mean.chrf.unwrap()), 44.18);
 
     // Round 2 asks again, encode first.
     let mut files = AnswerFiles::new(dao.run.next_round_dir().unwrap(), "fake-model".into());
@@ -1261,15 +1275,15 @@ fn refusal_stages_are_counted() {
     assert_eq!(r.train()[0].outcome, Outcome::Refused(Stage::Parse));
     assert_eq!(r.train()[0].packet, None);
     // A refused item is in the mean as 0: n counts every item, scored the real ones.
-    let m = r.train_mean();
+    let m = &r.language("en-US").unwrap().train_mean;
     assert_eq!((m.count, m.chrf, m.meaning), (1, Some(0.0), Some(0.0)));
-    assert_eq!((r.train_scored(), r.validation_scored()), (0, 1));
-    assert_eq!(r.validation_refused().parse, 0);
+    assert_eq!((r.language("en-US").unwrap().train_scored, r.language("en-US").unwrap().validation_scored), (0, 1));
+    assert_eq!(r.language("en-US").unwrap().validation_refused.parse, 0);
     assert_eq!(
-        (r.validation_refused().admit, r.validation_refused().lower),
+        (r.language("en-US").unwrap().validation_refused.admit, r.language("en-US").unwrap().validation_refused.lower),
         (1, 0)
     );
-    let m = r.validation_mean();
+    let m = &r.language("en-US").unwrap().validation_mean;
     assert_eq!(m.count, 2);
     assert!(m.chrf.unwrap() > 0.0, "the relation item lowered and scored");
 
@@ -1291,29 +1305,29 @@ fn refusal_stages_are_counted() {
         None,
         "a refused packet is not stored"
     );
-    let v = b_only.validation_refused();
+    let v = b_only.language("en-US").unwrap().validation_refused;
     assert_eq!((v.parse, v.admit, v.lower), (1, 0, 0));
     assert_eq!(
-        b_only.validation_mean().count,
+        b_only.language("en-US").unwrap().validation_mean.count,
         2,
         "every Validation item counts"
     );
-    assert_eq!(b_only.validation_scored(), 1);
-    let b_half = b_only.validation_mean().chrf.unwrap();
+    assert_eq!(b_only.language("en-US").unwrap().validation_scored, 1);
+    let b_half = b_only.language("en-US").unwrap().validation_mean.chrf.unwrap();
     assert!(
         (b_half - 74.99 / 2.0).abs() < 0.01,
         "(74.99 + 0) / 2 = {b_half}"
     );
 
     let a_only = run([good_answers()[0].1.clone(), good_answers()[1].1.clone(), junk]);
-    assert_eq!(a_only.validation_refused().parse, 1);
-    let a_half = a_only.validation_mean().chrf.unwrap();
+    assert_eq!(a_only.language("en-US").unwrap().validation_refused.parse, 1);
+    let a_half = a_only.language("en-US").unwrap().validation_mean.chrf.unwrap();
     assert!(
         (a_half - 82.12 / 2.0).abs() < 0.01,
         "(82.12 + 0) / 2 = {a_half}"
     );
     // The halves add to the full mean: (a + 0) / 2 + (0 + b) / 2 = (a + b) / 2.
-    let whole = full.validation_mean().chrf.unwrap();
+    let whole = full.language("en-US").unwrap().validation_mean.chrf.unwrap();
     assert!(
         (a_half + b_half - whole).abs() < 1e-9,
         "{a_half} + {b_half} vs {whole}"
@@ -1322,7 +1336,7 @@ fn refusal_stages_are_counted() {
         b_half < whole && a_half < whole,
         "refusing never raises the mean"
     );
-    assert_eq!(full.validation_scored(), 2);
+    assert_eq!(full.language("en-US").unwrap().validation_scored, 2);
 }
 
 #[test]
@@ -1356,10 +1370,10 @@ fn non_utf8_encode_answer_is_a_parse_refusal() {
     let r = recorded(round(&mut dao.run, &mut files, &Scorer::new(Bag)).unwrap());
     assert_eq!(r.calls().len(), 5);
     // Item 3 is Validation: its refusal is a Parse refusal and the round stands.
-    let v = r.validation_refused();
+    let v = r.language("en-US").unwrap().validation_refused;
     assert_eq!((v.parse, v.admit, v.lower), (1, 0, 0));
-    assert_eq!((r.train_scored(), r.validation_scored()), (1, 1));
-    assert_eq!(r.validation_mean().count, 2);
+    assert_eq!((r.language("en-US").unwrap().train_scored, r.language("en-US").unwrap().validation_scored), (1, 1));
+    assert_eq!(r.language("en-US").unwrap().validation_mean.count, 2);
     assert_eq!(dao.run.rounds().unwrap(), [r]);
 }
 
@@ -1402,7 +1416,7 @@ fn a_failed_round_leaves_nothing_a_rerun_collides_with() {
         "{:?}",
         r.train()[0]
     );
-    assert_eq!(r.validation_refused(), Default::default());
+    assert_eq!(r.language("en-US").unwrap().validation_refused, Default::default());
     let stored = PacketStore::open(&dao.root.join("round-1/packets.cc"))
         .unwrap()
         .all()
@@ -1441,7 +1455,7 @@ fn a_stale_packet_store_in_an_unrecorded_round_dir_is_discarded_at_start() {
         "the revised draft is not refused as a changed packet: {:?}",
         r.train()[0]
     );
-    assert_eq!(r.validation_refused(), Default::default());
+    assert_eq!(r.language("en-US").unwrap().validation_refused, Default::default());
     let stored = PacketStore::open(&dir.join("packets.cc"))
         .unwrap()
         .all()
@@ -1467,11 +1481,11 @@ fn the_round_line_prints_each_split_under_its_own_name() {
     let r = recorded(round(&mut dao.run, &mut model, &Scorer::new(Bag)).unwrap());
     let line = dao.run.round_line(&r);
     // Train is item 1 alone, Validation items 2 and 3; the numbers differ.
-    let (t, v) = (r.train_mean(), r.validation_mean());
+    let (t, v) = (&r.language("en-US").unwrap().train_mean, &r.language("en-US").unwrap().validation_mean);
     assert_eq!(
         line,
         format!(
-            "round 1 rev 3 train n=1 scored=1 chrf={:.2} meaning={:.4} refused=0 validation n=2 scored=2 chrf={:.2} meaning={:.4} refused parse=0 admit=0 lower=0 lowering=tool-less-relay",
+            "round 1 rev 3 en-US train n=1 scored=1 chrf={:.2} meaning={:.4} refused=0 validation n=2 scored=2 chrf={:.2} meaning={:.4} refused parse=0 admit=0 lower=0 lowering=tool-less-relay",
             t.chrf.unwrap(),
             t.meaning.unwrap(),
             v.chrf.unwrap(),
@@ -1522,6 +1536,7 @@ fn errors_echo_no_input() {
         "bag",
         weksa::run::LowererReach::ToolLessRelay,
         ModelFamily::Unrecorded,
+        &["en-US".to_string()],
     )
     .err()
     .unwrap();
@@ -1534,6 +1549,7 @@ fn errors_echo_no_input() {
         "bag",
         weksa::run::LowererReach::ToolLessRelay,
         ModelFamily::Unrecorded,
+        &["en-US".to_string()],
     )
     .err()
     .unwrap();
@@ -1546,6 +1562,7 @@ fn errors_echo_no_input() {
         "bag",
         weksa::run::LowererReach::ToolLessRelay,
         ModelFamily::Unrecorded,
+        &["en-US".to_string()],
     )
     .err()
     .unwrap();
@@ -1583,6 +1600,7 @@ fn errors_echo_no_input() {
         "bag",
         weksa::run::LowererReach::ToolLessRelay,
         ModelFamily::Unrecorded,
+        &["en-US".to_string()],
     )
     .unwrap();
     let mut model = cycle_fake(&format!("{{\"{canary}\":1}}"));
@@ -1717,13 +1735,13 @@ fn head_rev(root: &Path) -> u32 {
 }
 
 fn validation(r: &RoundRecord) -> Reading {
-    Reading::of(r.validation_mean()).unwrap()
+    Reading::of(&r.language("en-US").unwrap().validation_mean).unwrap()
 }
 
 /// The feedback line the editor is shown for a head round, built from outside.
 fn feedback_line(last: &str, head: &RoundRecord) -> String {
     let rounded = (validation(head).composite / LADDER_STEP).round() * LADDER_STEP;
-    format!("last edit: {last}; validation composite at head: {rounded:.3}")
+    format!("last edit: {last}; validation composite at head: en-US {rounded:.3}")
 }
 
 fn mint_texts(model: &FakeModel) -> Vec<&str> {
@@ -1751,19 +1769,19 @@ fn cycle_accepts_a_gain_past_the_floor() {
     );
     assert_eq!((d.base_rev(), d.candidate_rev()), (3, Some(4)));
     assert_eq!(d.verdict(), Verdict::Accepted);
-    assert_eq!(d.threshold(), LADDER_STEP);
+    assert_eq!(d.panel()[0].threshold, LADDER_STEP);
     assert_eq!(
-        *d.floor(),
+        d.panel()[0].floor,
         Reading {
             chrf: 0.0,
             meaning: 0.0,
             composite: 0.0
         }
     );
-    assert_eq!(*d.base(), validation(&rounds[0]));
+    assert_eq!(d.panel()[0].base, validation(&rounds[0]));
     let record = dao.run.rounds().unwrap().remove(2);
-    assert_eq!(d.candidate(), Some(&validation(&record)));
-    assert!(d.candidate().unwrap().composite - d.base().composite > LADDER_STEP);
+    assert_eq!(d.panel()[0].candidate, Some(validation(&record)));
+    assert!(d.panel()[0].candidate.unwrap().composite - d.panel()[0].base.composite > LADDER_STEP);
 
     // The candidate round was scored under the candidate file, as cycle 1's.
     let file = dao.root.join("cycle-1/inventory.cc");
@@ -1787,11 +1805,11 @@ fn cycle_accepts_a_gain_past_the_floor() {
     assert_eq!(d.edit().prompt, model.seen[0].0);
 
     // The line, with the readings printed to four places.
-    let (b, c) = (d.base().composite, d.candidate().unwrap().composite);
+    let (b, c) = (d.panel()[0].base.composite, d.panel()[0].candidate.unwrap().composite);
     assert_eq!(
         dao.run.cycle_line(&d),
         format!(
-            "cycle 1 rev 3->4 base={b:.4} candidate={c:.4} floor=0.0000 threshold=0.0050 accepted lowering=tool-less-relay"
+            "cycle 1 rev 3->4 en-US base={b:.4} candidate={c:.4} floor=0.0000 threshold=0.0050 accepted lowering=tool-less-relay"
         )
     );
 
@@ -1822,7 +1840,7 @@ fn cycle_accepts_a_gain_past_the_floor() {
     assert_eq!(d2.candidate_rev(), Some(5));
     assert_eq!(d2.candidate_round(), Some(5));
     assert_eq!(d2.verdict(), Verdict::Rejected(Why::NoGain));
-    assert_eq!(*d2.floor(), *d.floor(), "the floor is measured once");
+    assert_eq!(d2.panel()[0].floor, d.panel()[0].floor, "the floor is measured once");
     assert_eq!(head_rev(&dao.root), 4, "a rejected edit moves nothing");
     assert!(
         mint_texts(&second)[0].contains(&feedback_line("accepted", &dao.run.rounds().unwrap()[2])),
@@ -1846,12 +1864,12 @@ fn cycle_rejects_no_gain_and_keeps_the_head() {
     let d = run_cycle(&mut dao, &mut model);
     assert_eq!(d.verdict(), Verdict::Rejected(Why::NoGain));
     assert_eq!((d.candidate_rev(), d.candidate_round()), (Some(4), Some(3)));
-    assert_eq!(d.candidate(), Some(d.base()));
-    let c = d.base().composite;
+    assert_eq!(d.panel()[0].candidate, Some(d.panel()[0].base));
+    let c = d.panel()[0].base.composite;
     assert_eq!(
         dao.run.cycle_line(&d),
         format!(
-            "cycle 1 rev 3->4 base={c:.4} candidate={c:.4} floor=0.0000 threshold=0.0050 rejected no-gain lowering=tool-less-relay"
+            "cycle 1 rev 3->4 en-US base={c:.4} candidate={c:.4} floor=0.0000 threshold=0.0050 rejected no-gain lowering=tool-less-relay"
         )
     );
     assert_eq!(head_rev(&dao.root), 3);
@@ -1911,10 +1929,10 @@ fn distinct_replicates_set_the_floor_and_a_gain_inside_it_is_no_gain() {
     // (round 1) is the floor, which is past a step and inside the noise.
     let mut model = cycle_fake(ONE_CONCEPT);
     let d = run_cycle(&mut dao, &mut model);
-    assert_eq!(*d.floor(), want);
-    assert_eq!(d.threshold(), want.composite);
-    assert_eq!(d.candidate(), Some(&b));
-    assert!(d.candidate().unwrap().composite - d.base().composite > LADDER_STEP);
+    assert_eq!(d.panel()[0].floor, want);
+    assert_eq!(d.panel()[0].threshold, want.composite);
+    assert_eq!(d.panel()[0].candidate, Some(b));
+    assert!(d.panel()[0].candidate.unwrap().composite - d.panel()[0].base.composite > LADDER_STEP);
     assert_eq!(d.verdict(), Verdict::Rejected(Why::NoGain));
     assert_eq!(head_rev(&dao.root), 3);
 }
@@ -2101,7 +2119,7 @@ fn unanswered_cycle_writes_nothing() {
     let mint = std::fs::read_to_string(&mint_file).unwrap();
     assert_eq!(format!("{:016x}", fnv1a64(mint.as_bytes())), asked[0]);
     assert!(mint.starts_with(MINT_INSTRUCTIONS));
-    assert!(mint.contains("\n\nlast edit: none; validation composite at head: 0.435\n\n"));
+    assert!(mint.contains("\n\nlast edit: none; validation composite at head: en-US 0.435\n\n"));
     assert!(mint.contains("\n\ninventory rev:3\n"));
     assert_eq!(mint.matches("[item:").count(), 1, "one Train block");
     assert_eq!(std::fs::read_dir(&dir).unwrap().count(), 1);
@@ -2349,7 +2367,7 @@ fn edit_refusals_are_decisions() {
         let d = run_cycle(&mut dao, &mut model);
         assert_eq!(d.verdict(), Verdict::Rejected(why), "{name}");
         assert_eq!(
-            (d.candidate_rev(), d.candidate_round(), d.candidate()),
+            (d.candidate_rev(), d.candidate_round(), d.panel()[0].candidate),
             (None, None, None),
             "{name}"
         );
@@ -2377,8 +2395,8 @@ fn edit_refusals_are_decisions() {
         assert_eq!(
             dao.run.cycle_line(&d),
             format!(
-                "cycle 1 rev 3->none base={:.4} candidate=none floor=0.0000 threshold=0.0050 rejected {tag} lowering=tool-less-relay",
-                d.base().composite
+                "cycle 1 rev 3->none en-US base={:.4} candidate=none floor=0.0000 threshold=0.0050 rejected {tag} lowering=tool-less-relay",
+                d.panel()[0].base.composite
             ),
             "{name}"
         );
@@ -2419,20 +2437,8 @@ fn cycle_needs_a_floor() {
         "the run has no noise floor: record two rounds first"
     );
 
-    // Rounds whose Validation items are all withdrawn have no reading.
-    let mut dao = dao_over(|corpus, _| {
-        let mut store = weksa::CorpusStore::open(corpus).unwrap();
-        for n in [2, 3] {
-            store.withdraw(&format!("item:daodejing:{n}")).unwrap();
-        }
-    });
-    for _ in 0..2 {
-        let mut m = fake(&[(1, json(&draft_of(1)))]);
-        let r = recorded(round(&mut dao.run, &mut m, &Scorer::new(Bag)).unwrap());
-        assert_eq!(r.validation_mean().count, 0);
-    }
-    let mut model = cycle_fake(ONE_CONCEPT);
-    assert_eq!(none(&mut dao, &mut model), Some(RunError::NoValidation));
+    // A panel language with no live Validation item never reaches a round:
+    // `create` refuses it (open_refuses_a_bad_panel).
     assert_eq!(
         RunError::NoValidation.to_string(),
         "a reading has no validation item"
@@ -2515,6 +2521,7 @@ fn a_changed_head_is_drift() {
         "bag",
         weksa::run::LowererReach::ToolLessRelay,
         ModelFamily::Unrecorded,
+        &["en-US".to_string()],
     )
     .unwrap();
     assert_eq!(
@@ -2673,6 +2680,11 @@ fn the_lowerer_sees_no_item_text() {
         item.text = "CANARYVALIDATIONTEXT of the zebra".into();
         item.names = vec![];
         item.prior_turns = vec![];
+        store.add(item.clone(), &entities).unwrap();
+        // A held-out ja-JP line too: the panel is en-US, so it is never offered.
+        item.id = "item:canary:2".into();
+        item.text = "CANARYJAPANESE 検証テキスト".into();
+        item.language = "ja-JP".into();
         store.add(item, &entities).unwrap();
     });
     let mut model = fake(&good_answers());
@@ -2682,7 +2694,7 @@ fn the_lowerer_sees_no_item_text() {
 
     let corpus = weksa::CorpusStore::open(&dao.corpus).unwrap();
     let items = corpus.all().unwrap();
-    assert!(items.len() >= 6, "the canary and the five Legge items");
+    assert!(items.len() >= 7, "the canaries and the five Legge items");
     let packet_keys: Vec<String> = PacketStore::open(&dao.root.join("round-1/packets.cc"))
         .unwrap()
         .all()
@@ -2772,10 +2784,10 @@ fn lowering_refusals_count_at_lower() {
             r.train()[0].packet.is_some(),
             "{what}: the admitted packet is kept on the Train row"
         );
-        let v = r.validation_refused();
+        let v = r.language("en-US").unwrap().validation_refused;
         assert_eq!((v.parse, v.admit, v.lower), (0, 0, 2), "{what}");
-        assert_eq!((r.train_scored(), r.validation_scored()), (0, 0), "{what}");
-        let m = r.validation_mean();
+        assert_eq!((r.language("en-US").unwrap().train_scored, r.language("en-US").unwrap().validation_scored), (0, 0), "{what}");
+        let m = &r.language("en-US").unwrap().validation_mean;
         assert_eq!((m.count, m.chrf), (2, Some(0.0)), "{what}");
     }
 }
@@ -2851,6 +2863,7 @@ fn a_summary_line_says_how_lowerings_were_answered() {
         "bag",
         LowererReach::BriefedSubagent,
         ModelFamily::Unrecorded,
+        &["en-US".to_string()],
     )
     .unwrap();
     let run = RunStores::open(&root).unwrap();
@@ -2873,12 +2886,12 @@ fn lowering_text_at_the_bound_is_scored_and_line_breaks_are_text() {
         model.raw_lowering = Some(Ok(serde_json::json!({ "text": text }).to_string()));
         let r = recorded(round(&mut dao.run, &mut model, &Scorer::new(Bag)).unwrap());
         assert_eq!(
-            (r.train_scored(), r.validation_scored()),
+            (r.language("en-US").unwrap().train_scored, r.language("en-US").unwrap().validation_scored),
             (1, 2),
             "{}",
             text.len()
         );
-        assert_eq!(r.validation_refused(), Default::default());
+        assert_eq!(r.language("en-US").unwrap().validation_refused, Default::default());
     }
 }
 
@@ -2934,9 +2947,9 @@ fn a_lowering_prompt_that_cannot_be_built_refuses_at_lower_and_keeps_the_packet(
     let kept = row.packet.as_deref().expect("the admitted packet's key is kept");
     let packets = PacketStore::open(&dao.root.join("round-1/packets.cc")).unwrap();
     assert!(packets.get(kept).unwrap().is_some());
-    let v = r.validation_refused();
+    let v = r.language("en-US").unwrap().validation_refused;
     assert_eq!((v.parse, v.admit, v.lower), (0, 0, 1));
-    assert_eq!((r.train_scored(), r.validation_scored()), (1, 2));
+    assert_eq!((r.language("en-US").unwrap().train_scored, r.language("en-US").unwrap().validation_scored), (1, 2));
     // Five items encoded, three lowering prompts built and asked.
     assert_eq!(r.calls().len(), 5 + 3);
 }
@@ -3145,7 +3158,7 @@ fn parse_reasons_never_echo_answer() {
         a[1].1 = answer;
         let mut model = fake(&a);
         let r = recorded(round(&mut dao.run, &mut model, &Scorer::new(Bag)).unwrap());
-        assert_eq!(r.validation_refused().parse, 1);
+        assert_eq!(r.language("en-US").unwrap().validation_refused.parse, 1);
         let line = dao.run.round_line(&r);
         assert!(!line.contains(canary) && !line.contains("CANARY"), "{line}");
         let bytes = std::fs::read(dao.root.join("run.cc")).unwrap();
@@ -3154,7 +3167,7 @@ fn parse_reasons_never_echo_answer() {
     }
 }
 
-/// A run record as written before `answerer_family` (key 13) existed.
+/// A run record as written before `answerer_family` (key 13) and `panel` (key 14) existed.
 #[derive(Clone, Debug, schemars::JsonSchema, cultcache_rs::DatabaseEntry)]
 #[cultcache(type = "weksa.loop_run")]
 struct PreFamilyRun {
@@ -3184,8 +3197,8 @@ struct PreFamilyRun {
     lowerer_reach: weksa::run::LowererReach,
 }
 
-/// A round record as written before `parse_reasons` and `own_family`, and
-/// before `admit_rules` had a default.
+/// A round record as written with the pooled means (keys 11 to 15) and before
+/// `parse_reasons`, `own_family` and `languages`.
 #[derive(Clone, Debug, schemars::JsonSchema, cultcache_rs::DatabaseEntry)]
 #[cultcache(type = "weksa.loop_round")]
 struct LegacyRound {
@@ -3226,7 +3239,7 @@ struct LegacyRound {
 }
 
 #[test]
-fn records_from_before_the_new_fields_decode_with_defaults() {
+fn a_run_from_before_does_not_open() {
     let mut dao = dao();
     let mut model = fake(&good_answers());
     let r = recorded(round(&mut dao.run, &mut model, &Scorer::new(Bag)).unwrap());
@@ -3243,11 +3256,11 @@ fn records_from_before_the_new_fields_decode_with_defaults() {
         chrf_version: r.chrf_version().into(),
         calls: r.calls().to_vec(),
         train: r.train().to_vec(),
-        train_mean: r.train_mean().clone(),
-        validation_mean: r.validation_mean().clone(),
-        validation_refused: r.validation_refused(),
-        train_scored: r.train_scored(),
-        validation_scored: r.validation_scored(),
+        train_mean: r.language("en-US").unwrap().train_mean.clone(),
+        validation_mean: r.language("en-US").unwrap().validation_mean.clone(),
+        validation_refused: r.language("en-US").unwrap().validation_refused,
+        train_scored: r.language("en-US").unwrap().train_scored,
+        validation_scored: r.language("en-US").unwrap().validation_scored,
         inventory_digest: r.inventory_digest().into(),
         cycle: r.cycle(),
     };
@@ -3266,25 +3279,33 @@ fn records_from_before_the_new_fields_decode_with_defaults() {
         lowerer_reach: rec.lowerer_reach,
     };
     drop(dao.run);
-    let mut cache = CultCache::new();
-    cache.register_entry_type::<PreFamilyRun>().unwrap();
-    cache.register_entry_type::<LegacyRound>().unwrap();
-    cache
-        .add_generic_backing_store(SingleFileMessagePackBackingStore::new(root.join("run.cc")))
-        .unwrap();
-    cache.pull_all_backing_stores().unwrap();
-    cache.put("run:dao".to_string(), &run).unwrap();
-    cache.put("run:dao:round:1".to_string(), &legacy).unwrap();
-    drop(cache);
-
+    let store = || SingleFileMessagePackBackingStore::new(root.join("run.cc"));
+    // A run record without a panel (no key 14) is a scratch run off git.
+    {
+        let mut cache = CultCache::new();
+        cache.register_entry_type::<PreFamilyRun>().unwrap();
+        cache.register_entry_type::<LegacyRound>().unwrap();
+        cache.add_generic_backing_store(store()).unwrap();
+        cache.pull_all_backing_stores().unwrap();
+        cache.put("run:dao".to_string(), &run).unwrap();
+        cache.put("run:dao:round:1".to_string(), &legacy).unwrap();
+    }
+    assert_eq!(RunStores::open(&root).err(), Some(RunError::Store));
+    // A round with the pooled means (keys 11 to 15) and no languages is
+    // unreadable, under a record that has its panel.
+    let _ = std::fs::remove_file(root.join("run.cc"));
+    {
+        let mut cache = CultCache::new();
+        cache.register_entry_type::<RunRecord>().unwrap();
+        cache.register_entry_type::<LegacyRound>().unwrap();
+        cache.add_generic_backing_store(store()).unwrap();
+        cache.pull_all_backing_stores().unwrap();
+        cache.put("run:dao".to_string(), &rec).unwrap();
+        cache.put("run:dao:round:1".to_string(), &legacy).unwrap();
+    }
+    // No round of that run can be read: it stops at its first round or cycle.
     let reopened = RunStores::open(&root).unwrap();
-    assert_eq!(reopened.record().answerer_family, ModelFamily::Unrecorded);
-    let rounds = reopened.rounds().unwrap();
-    assert_eq!(rounds.len(), 1);
-    assert_eq!(rounds[0].n(), 1);
-    assert!(rounds[0].admit_rules().is_empty());
-    assert!(rounds[0].parse_reasons().is_empty());
-    assert_eq!(rounds[0].own_family(), 0);
+    assert!(reopened.rounds().is_err());
 }
 
 #[test]
@@ -3310,10 +3331,24 @@ fn the_published_run_and_round_schemas_require_none_of_the_new_fields() {
     }
 }
 
-/// Answers a recall probe from the corpus: the item's own second half, a
-/// fixed wrong text, or junk.
+/// What a recall prompt shows of its item: the text after `opening: `.
+fn shown_opening(prompt: &str) -> &str {
+    prompt.rsplit_once("opening: ").expect("a recall prompt has an opening").1
+}
+
+/// The item's text after the opening the prompt showed.
+fn held_back<'a>(text: &'a str, prompt: &str) -> &'a str {
+    let opening = shown_opening(prompt);
+    text.strip_prefix(opening)
+        .unwrap_or_else(|| panic!("the opening is a prefix of the item"))
+        .trim()
+}
+
+/// Answers a recall probe from the corpus: the item's own held-back half (its
+/// text after the opening the prompt showed), a fixed wrong text, or junk.
 struct Reciter {
     corpus: weksa::store::CorpusStore,
+    /// Given the item's held-back half.
     answer: fn(&str) -> String,
     /// An item whose text holds this gets an answer file that is not UTF-8.
     unreadable: Option<&'static str>,
@@ -3331,14 +3366,12 @@ impl ModelPort for Reciter {
         if self.unreadable.is_some_and(|t| item.text.contains(t)) {
             return Err(PortError::Io(std::io::ErrorKind::InvalidData));
         }
-        Ok((self.answer)(&item.text))
+        Ok((self.answer)(held_back(&item.text, prompt.text())))
     }
 }
 
-fn second_half(text: &str) -> String {
-    let words: Vec<&str> = text.split_whitespace().collect();
-    let draft = serde_json::json!({ "text": words[words.len() / 2..].join(" ") });
-    draft.to_string()
+fn second_half(held_back: &str) -> String {
+    serde_json::json!({ "text": held_back }).to_string()
 }
 
 fn reciter(dao: &Dao, answer: fn(&str) -> String) -> Reciter {
@@ -3355,20 +3388,26 @@ fn a_recall_probe_asks_for_the_second_half_of_each_live_item_and_never_shows_it(
     use weksa::run::RecallOutcome;
     let dao = dao();
     let mut perfect = reciter(&dao, second_half);
-    let RecallOutcome::Read(r) = dao.run.recall(&mut perfect).unwrap() else {
+    let RecallOutcome::Read(reading) = dao.run.recall(&mut perfect).unwrap() else {
         panic!("every prompt was answered");
     };
+    let r = reading.languages[0].clone();
     // Items 1 (Train) and 2, 3 (Validation) are live; 4 and 5 are not offered.
     assert_eq!((r.n, r.answered), (3, 3));
     assert!((r.chrf - 100.0).abs() < 1e-9, "{}", r.chrf);
     assert_eq!(perfect.seen.len(), 3);
     for (text, key) in perfect.seen.iter().zip(["item:daodejing:1", "item:daodejing:2", "item:daodejing:3"]) {
         let item = perfect.corpus.get(key).unwrap().unwrap();
-        let rest = item.text.split_whitespace().collect::<Vec<_>>();
-        let tail = rest[rest.len() / 2..].join(" ");
-        let head = rest[..rest.len() / 2].join(" ");
-        assert!(text.contains(&head), "{key}: the opening is shown");
-        assert!(!text.contains(&tail), "{key}: the held half is not shown");
+        // The opening is a proper prefix of the item, cut at a word boundary
+        // near its middle; the rest is held back.
+        let head = shown_opening(text);
+        let tail = held_back(&item.text, text);
+        assert!(!head.is_empty() && !tail.is_empty(), "{key}");
+        let squeeze = |t: &str| t.split_whitespace().collect::<String>();
+        assert_eq!(squeeze(&item.text), squeeze(&format!("{head}{tail}")), "{key}: head and tail are the item");
+        let n = item.text.len();
+        assert!((n / 4..=3 * n / 4).contains(&head.len()), "{key}: near the middle");
+        assert!(!text.contains(tail), "{key}: the held half is not shown");
     }
 }
 
@@ -3377,15 +3416,17 @@ fn a_recall_of_the_wrong_words_or_no_answer_reads_low_and_a_missing_answer_waits
     use weksa::run::RecallOutcome;
     let dao = dao();
     let mut wrong = reciter(&dao, |_| r#"{"text":"zzz qqq xxx"}"#.to_string());
-    let RecallOutcome::Read(r) = dao.run.recall(&mut wrong).unwrap() else {
+    let RecallOutcome::Read(reading) = dao.run.recall(&mut wrong).unwrap() else {
         panic!("answered");
     };
+    let r = reading.languages[0].clone();
     assert_eq!((r.n, r.answered), (3, 3));
     assert!(r.chrf < 10.0, "{}", r.chrf);
     let mut junk = reciter(&dao, |_| "not json".to_string());
-    let RecallOutcome::Read(r) = dao.run.recall(&mut junk).unwrap() else {
+    let RecallOutcome::Read(reading) = dao.run.recall(&mut junk).unwrap() else {
         panic!("answered");
     };
+    let r = reading.languages[0].clone();
     assert_eq!((r.n, r.answered, r.chrf), (3, 0, 0.0));
     // With no answers on disk the files port waits on all three prompts.
     let mut files = AnswerFiles::new(dao.run.recall_dir(), "m".into());
@@ -3429,10 +3470,10 @@ fn a_recall_mean_is_over_every_probe_an_unreadable_answer_counts_0_and_a_withdra
     let both = |dao: &Dao, unreadable: Option<&'static str>| {
         let mut m = reciter(dao, second_half);
         m.unreadable = unreadable;
-        let RecallOutcome::Read(r) = dao.run.recall(&mut m).unwrap() else {
+        let RecallOutcome::Read(reading) = dao.run.recall(&mut m).unwrap() else {
             panic!("answered");
         };
-        r
+        reading.languages[0].clone()
     };
     let full = both(&dao, None);
     assert_eq!(
@@ -3541,16 +3582,17 @@ fn mixed_family_round(family: ModelFamily) -> u32 {
         "bag",
         LowererReach::ToolLessRelay,
         family,
+        &["en-US".to_string()],
     )
     .unwrap();
     let scorer = weksa::score::Scorer::new(OneBag);
     match round(&mut run, &mut NotADraft, &scorer).unwrap() {
         RoundOutcome::Recorded(r) => {
-            // Seven items were offered: the world's own cast item and mix 1 to 6;
+            // Eight items were offered: the world's two cast items and mix 1 to 6;
             // the Test-group and withdrawn items were not.
             assert_eq!(
                 r.parse_reasons().iter().map(|c| c.count).sum::<u32>(),
-                7,
+                8,
                 "offered items"
             );
             r.own_family()
@@ -3697,7 +3739,7 @@ fn read(
     outcome: weksa::run::AblationOutcome,
 ) -> Vec<(weksa::Split, weksa::run::AblationReading)> {
     match outcome {
-        weksa::run::AblationOutcome::Read(r) => r,
+        weksa::run::AblationOutcome::Read(r) => r.into_iter().map(|(_, split, x)| (split, x)).collect(),
         weksa::run::AblationOutcome::Unanswered { prompts } => panic!("unanswered {prompts:?}"),
     }
 }
@@ -4109,3 +4151,409 @@ fn a_split_where_no_replay_is_usable_reads_none_throughout() {
         "ablation n=0 unusable=2 replay chrf=none meaning=none | drop n=0 chrf=none meaning=none moved=0 ref_gain_chrf=none ref_gain_meaning=none | permute n=0 chrf=none meaning=none moved=0 ref_gain_chrf=none ref_gain_meaning=none"
     );
 }
+
+// ---- the panel: each item is lowered in its own language ----
+
+const JA_TEXTS: [(&str, &str, usize); 3] = [
+    ("item:daodejing:11", "賢者は民の心を空にし、腹を満たし、志を弱め、骨を強くする。", 1),
+    ("item:daodejing:12", "天は長く、地は久しい。", 2),
+    ("item:daodejing:13", "上善は水のようである。", 3),
+];
+
+/// The Dao corpus with a ja-JP twin of each live item (same group, so the same
+/// split) and a pt-BR twin of each; Laozi, the speaker the packets cite, gains
+/// `ja` as a ja-JP form when given.
+fn add_languages(corpus: &Path, entities: &Path, ja: Option<&str>) {
+    let mut entities = weksa::EntityStore::open(entities).unwrap();
+    if let Some(form) = ja {
+        let mut laozi = entities.get(&common::eid("laozi")).unwrap().unwrap();
+        laozi.forms.push(weksa::LanguageForms {
+            language: "ja-JP".into(),
+            forms: vec![form.into()],
+            pronunciation: None,
+        });
+        entities.put(laozi).unwrap();
+    }
+    let mut store = CorpusStore::open(corpus).unwrap();
+    for (key, text, twin) in JA_TEXTS {
+        let mut item = store.get(&format!("item:daodejing:{twin}")).unwrap().unwrap();
+        item.id = key.into();
+        item.text = text.into();
+        item.language = "ja-JP".into();
+        item.names = vec![];
+        item.prior_turns = vec![];
+        store.add(item, &entities).unwrap();
+        let mut pt = store.get(&format!("item:daodejing:{twin}")).unwrap().unwrap();
+        pt.id = format!("item:daodejing:2{twin}");
+        pt.text = format!("PORTUGUESEMARK {twin} o sabio esvazia os coracoes");
+        pt.language = "pt-BR".into();
+        pt.names = vec![];
+        pt.prior_turns = vec![];
+        store.add(pt, &entities).unwrap();
+    }
+}
+
+/// The Dao draft of `item`, its first referent citing the speaker, Laozi.
+fn citing_laozi(item: usize) -> String {
+    let mut v = serde_json::to_value(draft_of(item)).unwrap();
+    v["referents"][0]["entity"] = serde_json::json!("entity:laozi");
+    v.to_string()
+}
+
+/// Encode answers for the en-US and ja-JP items, all citing the sage.
+fn bilingual_answers() -> HashMap<String, String> {
+    let mut answers = HashMap::new();
+    for n in 1..=3 {
+        answers.insert(format!("item:daodejing:{n}"), citing_laozi(n));
+        answers.insert(format!("item:daodejing:1{n}"), citing_laozi(n));
+    }
+    answers
+}
+
+fn bilingual_fake() -> FakeModel {
+    let mut model = fake(&[]);
+    model.answers = bilingual_answers();
+    for (key, text, _) in JA_TEXTS {
+        model.lowered.insert(key.into(), text.into());
+    }
+    model
+}
+
+fn bilingual(ja: Option<&'static str>) -> Dao {
+    dao_panel(
+        |corpus, entities| add_languages(corpus, entities, ja),
+        &["ja-JP", "en-US"],
+    )
+}
+
+const LAOZI_JA: Option<&str> = Some("老子");
+
+fn lowering_texts(model: &FakeModel) -> Vec<&str> {
+    model
+        .seen
+        .iter()
+        .map(|(_, t)| t.as_str())
+        .filter(|t| t.starts_with(LOWER_INSTRUCTIONS))
+        .collect()
+}
+
+#[test]
+fn each_item_lowers_in_its_own_language() {
+    let mut dao = bilingual(LAOZI_JA);
+    assert_eq!(dao.run.record().panel, ["en-US", "ja-JP"], "sorted at open");
+    let mut model = bilingual_fake();
+    let r = recorded(round(&mut dao.run, &mut model, &Scorer::new(Bag)).unwrap());
+    let prompts = lowering_texts(&model);
+    assert_eq!(prompts.len(), 6, "three items in each language");
+    let (mut ja, mut en) = (0, 0);
+    for text in prompts {
+        if text.contains("\n\nlanguage: ja-JP\n\n") {
+            ja += 1;
+            assert!(text.contains(r#"{"entity:laozi":["老子"]}"#), "{text}");
+            assert!(!text.contains("Laozi"), "{text}");
+        } else {
+            en += 1;
+            assert!(text.contains("\n\nlanguage: en-US\n\n"), "{text}");
+            assert!(text.contains(r#"{"entity:laozi":["Laozi"]}"#), "{text}");
+            assert!(!text.contains("老子"), "{text}");
+        }
+    }
+    assert_eq!((ja, en), (3, 3));
+    // No lowering prompt, in either language, holds any item's text, key or group.
+    let corpus = CorpusStore::open(&dao.corpus).unwrap();
+    for text in lowering_texts(&model) {
+        for item in corpus.all().unwrap() {
+            assert!(!text.contains(&item.text), "{}", item.id);
+            assert!(!text.contains(item.id.as_str()), "{}", item.id);
+            assert!(!text.contains(item.group.as_str()), "{}", item.id);
+        }
+    }
+    // A ja-JP item is scored against its own text: the lowering that is the
+    // text reads as a perfect one.
+    let ja = r.language("ja-JP").unwrap();
+    assert_eq!((ja.train_scored, ja.validation_scored), (1, 2));
+    assert_eq!(ja.validation_mean.chrf, Some(100.0));
+    assert_eq!(ja.train_mean.meaning, Some(1.0));
+}
+
+#[test]
+fn a_cited_entity_without_a_form_in_the_items_language_refuses_at_lower() {
+    let mut dao = bilingual(None);
+    let mut model = bilingual_fake();
+    let r = recorded(round(&mut dao.run, &mut model, &Scorer::new(Bag)).unwrap());
+    let ja = r.language("ja-JP").unwrap();
+    assert_eq!(ja.validation_refused.lower, 2);
+    assert_eq!((ja.train_scored, ja.validation_scored), (0, 0));
+    let refused: Vec<_> = r
+        .train()
+        .iter()
+        .filter(|row| matches!(row.outcome, Outcome::Refused(Stage::Lower)))
+        .collect();
+    assert_eq!(refused.len(), 1, "the ja-JP Train item");
+    assert_eq!(refused[0].item, "item:daodejing:11");
+    let en = r.language("en-US").unwrap();
+    assert_eq!((en.train_scored, en.validation_scored), (1, 2));
+    assert_eq!(en.validation_refused, weksa::run::RefusalCounts::default());
+    assert_eq!(lowering_texts(&model).len(), 3, "no prompt for a form that is missing");
+}
+
+#[test]
+fn the_panel_filters_every_prompt() {
+    let mut dao = bilingual(LAOZI_JA);
+    let mut model = bilingual_fake();
+    // Two rounds, a cycle (the editor's prompt), a recall: every kind of prompt.
+    let mut last = None;
+    for _ in 0..2 {
+        last = Some(recorded(round(&mut dao.run, &mut model, &Scorer::new(Bag)).unwrap()));
+    }
+    let tags = |r: &RoundRecord| -> Vec<String> {
+        r.languages().iter().map(|l| l.language.clone()).collect()
+    };
+    assert_eq!(tags(&last.unwrap()), ["en-US", "ja-JP"]);
+    model.candidate = Some((4, bilingual_answers()));
+    model.edit = Some(Ok(ONE_CONCEPT.to_string()));
+    run_cycle(&mut dao, &mut model);
+    let mut recite = reciter(&dao, second_half);
+    let reading = match dao.run.recall(&mut recite).unwrap() {
+        weksa::run::RecallOutcome::Read(r) => r,
+        _ => panic!("answered"),
+    };
+    let langs: Vec<&str> = reading.languages.iter().map(|l| l.language.as_str()).collect();
+    assert_eq!(langs, ["en-US", "ja-JP"]);
+    let shown = model.seen.iter().map(|(_, t)| t).chain(&recite.seen);
+    let mut count = 0;
+    for text in shown {
+        count += 1;
+        assert!(!text.contains("PORTUGUESE"), "a pt-BR item reached a prompt");
+        for n in 1..=3 {
+            assert!(!text.contains(&format!("item:daodejing:2{n}")));
+        }
+    }
+    assert!(count > 20, "{count}");
+    assert!(!mint_texts(&model).is_empty());
+    assert_eq!(dao.run.train().unwrap().len(), 2, "one Train item per panel language");
+}
+
+#[test]
+fn open_refuses_a_bad_panel() {
+    let train_only = |corpus: &Path, entities: &Path| {
+        let entities = weksa::EntityStore::open(entities).unwrap();
+        let mut store = CorpusStore::open(corpus).unwrap();
+        let mut item = store.get("item:daodejing:1").unwrap().unwrap();
+        item.id = "item:daodejing:31".into();
+        item.text = "Un texte francais.".into();
+        item.language = "fr-FR".into();
+        item.names = vec![];
+        item.prior_turns = vec![];
+        store.add(item, &entities).unwrap();
+    };
+    let dao = dao_over(train_only);
+    let (corpus, inventory, entities) = (&dao.corpus, &dao.inventory, &dao.entities);
+    drop(dao.run);
+    let tag = |s: &str| s.to_string();
+    for panel in [
+        vec![],
+        vec![tag("en-US"), tag("en-US")],
+        vec![tag("en-US"), tag("not a tag!")],
+        // No live item at all, and a Train item without a Validation one.
+        vec![tag("en-US"), tag("de-DE")],
+        vec![tag("en-US"), tag("fr-FR")],
+    ] {
+        let root = dao._dir.path().join(format!("panel-{}", panel.len()));
+        let created = RunStores::create(
+            &root,
+            "p",
+            RunPaths { corpus, inventory, entities },
+            "fake-model",
+            "bag",
+            weksa::run::LowererReach::ToolLessRelay,
+            ModelFamily::Unrecorded,
+            &panel,
+        );
+        let err = created.err();
+        assert_eq!(err, Some(RunError::Panel), "{panel:?}");
+        let shown = err.unwrap().to_string();
+        for t in &panel {
+            assert!(!shown.contains(t.as_str()), "{shown}");
+        }
+        assert!(!root.join("run.cc").exists(), "{panel:?}");
+        assert!(!root.join("inventory.cc").exists(), "{panel:?}");
+    }
+}
+
+#[test]
+fn round_means_are_per_language() {
+    let mut dao = bilingual(LAOZI_JA);
+    let mut model = bilingual_fake();
+    // One ja-JP Validation item is not an encodable draft: it counts 0.
+    model.answers.insert("item:daodejing:13".into(), "not a draft".into());
+    let r = recorded(round(&mut dao.run, &mut model, &Scorer::new(Bag)).unwrap());
+    let ja = r.language("ja-JP").unwrap();
+    // Validation: item 12 reads perfectly (chrF 100, meaning 1), item 13 is 0.
+    assert_eq!(ja.validation_mean.count, 2);
+    assert_eq!(ja.validation_mean.chrf, Some(50.0));
+    assert_eq!(ja.validation_mean.meaning, Some(0.5));
+    assert_eq!((ja.validation_scored, ja.validation_refused.parse), (1, 1));
+    assert_eq!(ja.train_mean.chrf, Some(100.0));
+
+    // en-US reads exactly as it does when it is the whole panel: the ja-JP
+    // items touch none of its numbers.
+    let mut alone = dao_over(|_, _| {});
+    let mut plain = fake(&good_answers());
+    let r2 = recorded(round(&mut alone.run, &mut plain, &Scorer::new(Bag)).unwrap());
+    assert_eq!(r.language("en-US"), r2.language("en-US"));
+    assert_eq!(r.languages().len(), 2);
+    assert_eq!(r2.languages().len(), 1);
+}
+
+#[test]
+fn floor_and_feedback_are_per_language() {
+    let mut dao = bilingual(LAOZI_JA);
+    // Round 1: everything lowers perfectly in ja-JP. Round 2: one ja-JP
+    // Validation item is refused. en-US reads the same twice.
+    let mut first = bilingual_fake();
+    recorded(round(&mut dao.run, &mut first, &Scorer::new(Bag)).unwrap());
+    let mut second = bilingual_fake();
+    second.answers.insert("item:daodejing:13".into(), "not a draft".into());
+    recorded(round(&mut dao.run, &mut second, &Scorer::new(Bag)).unwrap());
+
+    let mut model = bilingual_fake();
+    model.candidate = Some((4, bilingual_answers()));
+    model.edit = Some(Ok(ONE_CONCEPT.to_string()));
+    let d = run_cycle(&mut dao, &mut model);
+    let rows = d.panel();
+    assert_eq!(
+        rows.iter().map(|r| r.language.as_str()).collect::<Vec<_>>(),
+        ["en-US", "ja-JP"]
+    );
+    let (en, ja) = (&rows[0], &rows[1]);
+    assert_eq!(en.floor.composite, 0.0, "en-US read the same twice");
+    assert_eq!(en.threshold, LADDER_STEP);
+    assert_eq!(ja.floor.chrf, 50.0);
+    assert_eq!(ja.floor.meaning, 0.5);
+    assert_eq!(ja.floor.composite, 0.5);
+    assert_eq!(ja.threshold, 0.5);
+    assert_eq!(ja.base.composite, 1.0);
+
+    // The editor's one held-out number is each language's head composite on
+    // the ladder, in panel order.
+    let rounded = |x: f64| (x / LADDER_STEP).round() * LADDER_STEP;
+    let line = format!(
+        "last edit: none; validation composite at head: en-US {:.3}, ja-JP {:.3}",
+        rounded(en.base.composite),
+        rounded(ja.base.composite)
+    );
+    let mint = mint_texts(&model);
+    assert!(mint[0].contains(&format!("\n\n{line}\n\n")), "{}", mint[0]);
+}
+
+#[test]
+fn recall_probes_unspaced_lines() {
+    let dao = bilingual(LAOZI_JA);
+    let mut recite = reciter(&dao, second_half);
+    let reading = match dao.run.recall(&mut recite).unwrap() {
+        weksa::run::RecallOutcome::Read(r) => r,
+        _ => panic!("answered"),
+    };
+    let ja = reading.languages.iter().find(|l| l.language == "ja-JP").unwrap();
+    // Three lines written without spaces were skipped before.
+    assert_eq!((ja.n, ja.answered), (3, 3));
+    assert!((ja.chrf - 100.0).abs() < 1e-9);
+    let corpus = CorpusStore::open(&dao.corpus).unwrap();
+    for (key, ja_text, _) in JA_TEXTS {
+        let prompt = recite
+            .seen
+            .iter()
+            .find(|t| shown_opening(t).chars().next() == ja_text.chars().next())
+            .unwrap();
+        let item = corpus.get(key).unwrap().unwrap();
+        let (head, tail) = (shown_opening(prompt), held_back(&item.text, prompt));
+        assert!(!head.is_empty() && !tail.is_empty());
+        assert_eq!(format!("{head}{tail}"), item.text, "no spaces to lose");
+        let n = item.text.len();
+        assert!((n / 4..=3 * n / 4).contains(&head.len()), "{key}: near the byte middle");
+        assert!(!prompt.contains(tail));
+    }
+    // The unrelated-text floor was measured for English only: its clause
+    // prints once, on the en-US segment.
+    let line = reading.line();
+    assert_eq!(line.matches("unrelated English").count(), 1, "{line}");
+    let (first, second) = line.split_once(" | ").unwrap();
+    assert!(first.starts_with("recall en-US") && first.contains("unrelated English"), "{line}");
+    assert!(second.starts_with("recall ja-JP") && !second.contains("unrelated"), "{line}");
+    // en-US still splits between words.
+    let en = reading.languages.iter().find(|l| l.language == "en-US").unwrap();
+    assert_eq!((en.n, en.answered), (3, 3));
+    for key in ["item:daodejing:1", "item:daodejing:2", "item:daodejing:3"] {
+        let item = corpus.get(key).unwrap().unwrap();
+        let prompt = recite
+            .seen
+            .iter()
+            .find(|t| t.contains("opening: ") && item.text.starts_with(shown_opening(t)))
+            .unwrap();
+        let head = shown_opening(prompt);
+        let next = item.text[head.len()..].chars().next().unwrap();
+        assert!(!next.is_alphanumeric(), "{key}: cut inside a word");
+    }
+}
+
+#[test]
+fn offer_by_key_is_the_panels_too() {
+    let dao = bilingual(LAOZI_JA);
+    assert!(dao.run.offer("item:daodejing:12").unwrap().is_ok(), "ja-JP is in the panel");
+    assert!(dao.run.offer("item:daodejing:2").unwrap().is_ok());
+    for pt in ["item:daodejing:21", "item:daodejing:22", "item:daodejing:23"] {
+        assert!(dao.run.offer(pt).is_err(), "{pt}: pt-BR is outside the panel");
+    }
+}
+
+#[test]
+fn a_cycle_decides_each_language_on_its_own_floor() {
+    let mut dao = bilingual(LAOZI_JA);
+    // en-US reads the same twice (floor 0); ja-JP loses a Validation item in
+    // round 2 (a wide floor).
+    let mut first = bilingual_fake();
+    recorded(round(&mut dao.run, &mut first, &Scorer::new(Bag)).unwrap());
+    let mut second = bilingual_fake();
+    second.answers.insert("item:daodejing:13".into(), "not a draft".into());
+    recorded(round(&mut dao.run, &mut second, &Scorer::new(Bag)).unwrap());
+    // The candidate degrades en-US a little and leaves ja-JP as it was.
+    let mut model = bilingual_fake();
+    model.candidate = Some((4, {
+        let mut candidate = bilingual_answers();
+        candidate.extend(keyed(&degraded_answers()));
+        candidate
+    }));
+    model.edit = Some(Ok(ONE_CONCEPT.to_string()));
+    let d = run_cycle(&mut dao, &mut model);
+    let (en, ja) = (&d.panel()[0], &d.panel()[1]);
+    assert_eq!((en.language.as_str(), ja.language.as_str()), ("en-US", "ja-JP"));
+    assert_eq!(en.floor.chrf, 0.0);
+    assert_eq!(ja.floor.chrf, 50.0);
+    // en-US fell by more than its own floor but by less than ja-JP's: the
+    // verdict is the rejection that en-US's floor makes, not NoGain.
+    let fall = en.base.chrf - en.candidate.unwrap().chrf;
+    assert!(fall > 1.0 && fall < ja.floor.chrf, "{fall}");
+    assert!(matches!(d.verdict(), Verdict::Rejected(Why::Regressed(_))), "{:?}", d.verdict());
+}
+
+#[test]
+fn ablation_reads_each_language_apart() {
+    let mut dao = bilingual(LAOZI_JA);
+    let mut model = bilingual_fake();
+    recorded(round(&mut dao.run, &mut model, &Scorer::new(Bag)).unwrap());
+    let (mut rec, mut replay) = (bilingual_fake(), bilingual_fake());
+    let readings = match ablate(&dao, &mut rec, &mut replay).unwrap() {
+        weksa::run::AblationOutcome::Read(r) => r,
+        _ => panic!("answered"),
+    };
+    let shape: Vec<(&str, weksa::Split, u32)> = readings
+        .iter()
+        .map(|(l, split, r)| (l.as_str(), *split, r.n))
+        .collect();
+    use weksa::Split::{Train, Validation};
+    assert_eq!(
+        shape,
+        [("en-US", Train, 1), ("en-US", Validation, 2), ("ja-JP", Train, 1), ("ja-JP", Validation, 2)]
+    );
+}
diff --git a/crates/weksa/tests/original_corpus.rs b/crates/weksa/tests/original_corpus.rs
index 186cb2a..21f7a1d 100644
--- a/crates/weksa/tests/original_corpus.rs
+++ b/crates/weksa/tests/original_corpus.rs
@@ -238,12 +238,14 @@ fn the_recall_probe_covers_every_live_original_item_and_names_no_work() {
         "bag",
         weksa::run::LowererReach::BriefedSubagent,
         ModelFamily::Unrecorded,
+        &["en-US".to_string()],
     )
     .unwrap();
     let mut model = Unrelated(vec![]);
-    let RecallOutcome::Read(r) = run.recall(&mut model).unwrap() else {
+    let RecallOutcome::Read(reading) = run.recall(&mut model).unwrap() else {
         panic!("answered");
     };
+    let r = reading.languages[0].clone();
     assert_eq!((r.n, r.answered), (28, 28));
     assert!(r.chrf < 25.0, "{}", r.chrf);
     assert_eq!(model.0.len(), 28);
@@ -251,9 +253,12 @@ fn the_recall_probe_covers_every_live_original_item_and_names_no_work() {
     let all = CorpusStore::open(&c).unwrap().all().unwrap();
     for item in &all {
         let live = SplitScheme::V1.live(item);
-        // A recall prompt shows the first half of the words.
-        let words: Vec<&str> = item.text.split_whitespace().collect();
-        let opening = words[..words.len() / 2].join(" ");
+        // A recall prompt shows the first half of the item, cut at a word boundary.
+        let mut cut = item.text.len() / 4;
+        while !item.text.is_char_boundary(cut) {
+            cut -= 1;
+        }
+        let opening = item.text[..cut].trim_end().to_string();
         let shown = model.0.iter().any(|t| t.contains(&opening));
         assert_eq!(
             shown,
@@ -309,6 +314,7 @@ fn original_round(family: ModelFamily) -> (weksa::run::RunStores, weksa::run::Ro
         "bag",
         LowererReach::ToolLessRelay,
         family,
+        &["en-US".to_string()],
     )
     .unwrap();
     let scorer = weksa::score::Scorer::new(Bag);
@@ -416,9 +422,10 @@ fn recall_probes_only_live_train_and_validation_items() {
     drop(store);
     let run = run_over(dir.path());
     let mut m = Record(vec![]);
-    let RecallOutcome::Read(r) = run.recall(&mut m).unwrap() else {
+    let RecallOutcome::Read(reading) = run.recall(&mut m).unwrap() else {
         panic!("answered");
     };
+    let r = reading.languages[0].clone();
     assert_eq!(r.n, 2);
     let shown = |mark: &str| m.0.iter().any(|t| t.contains(mark));
     assert!(shown("trainmark") && shown("validmark"));
@@ -464,6 +471,7 @@ fn no_test_item_is_offered_to_a_round_or_recall_or_recorded() {
         "bag",
         LowererReach::ToolLessRelay,
         ModelFamily::Unrecorded,
+        &["en-US".to_string()],
     )
     .unwrap();
     let items = CorpusStore::open(&p("corpus.cc")).unwrap().all().unwrap();
@@ -499,9 +507,10 @@ fn no_test_item_is_offered_to_a_round_or_recall_or_recorded() {
         assert!(r.train().iter().all(|row| row.item != item.id));
     }
     let mut recall = Record(vec![]);
-    let weksa::run::RecallOutcome::Read(rr) = run.recall(&mut recall).unwrap() else {
+    let weksa::run::RecallOutcome::Read(reading) = run.recall(&mut recall).unwrap() else {
         panic!("answered");
     };
+    let rr = reading.languages[0].clone();
     assert_eq!((rr.n, rr.answered), (28, 28));
     for item in &held {
         assert!(!leaks(&recall.0, item), "recall prompt held {}", item.id);
diff --git a/docs/targets/dao-de-jing-test-bed.md b/docs/targets/dao-de-jing-test-bed.md
index 516e2e3..bd2ebbf 100644
--- a/docs/targets/dao-de-jing-test-bed.md
+++ b/docs/targets/dao-de-jing-test-bed.md
@@ -20,7 +20,7 @@ plus a separately recorded chosen gloss per lowering).
   is applied anywhere both meet.
 - Rebuild: `weksa --corpus C --inventory I --entities E` with `inventory seed`,
   `inventory proof`, `inventory dao`, `entity put entity:laozi ...`,
-  `corpus add ... --source public-domain` per item, then `packet dao <store>`.
+  `corpus add ... --language en-US --source public-domain` per item, then `packet dao <store>`.
 - Source: Project Gutenberg eBook 216, "The Tao Teh King, or the Tao and its
   Characteristics", Laozi, tr. James Legge (Sacred Books of the East 39, 1891).
   Gutenberg's licence (1.E.2) lets a work derived from texts not protected by US
diff --git a/docs/targets/interlingua-lowering-map.md b/docs/targets/interlingua-lowering-map.md
index 4846466..9c18e09 100644
--- a/docs/targets/interlingua-lowering-map.md
+++ b/docs/targets/interlingua-lowering-map.md
@@ -40,8 +40,8 @@ means no store holds it and nothing writes it.
 | Scene (cut `speaker-scene`) | Key `scene:<group>@<n>`, the item's split group; type `weksa.scene`: participants (speaker slugs) and, per ordered pair, relation features of slot `Scene` (relative status, intimacy, in-group, audience and whatever the loop adds), at an inventory revision, and an `Annotator` | As Speaker. Keyed by the group, so a scene never straddles the split | As Speaker |
 | Corpus item | Key `item:<source-slug>:<n>`, `n` canonical decimal >= 1 (no sign, no leading zero, from cut 2b); type `weksa.corpus_item` with text, language, speaker, split group, prior turns, source. Source `ModelWritten` carries a `ModelFamily` enum, the generator string as the fixture wrote it, and a prompt digest (cut 2b). The item carries no speaker state of its own: its speaker slug and group name the Speaker and Scene documents | Admitted once; the whole item is immutable (re-adding an identical item is a no-op, any difference is refused; a correction is a new item that `supersedes` the old); text already held under another key is refused unless the new item supersedes that key (cut 2b); withdrawn, never deleted, so old scores stay explainable | Importers and `weksa corpus add`, under `corpus-cast-plus-public-domain`; the source enum has no variant for Discord or any training-forbidden source (`corpus-clean`) |
 | Split assignment | Derived: `split(scheme, item.group)` | Fixed for a scheme; a new scheme is a new constant, never a reassignment. A model-written item whose group derives test is in no split; a superseding item keeps its predecessor's group | The hash function. Nobody assigns by hand, so there is no writer to forbid |
-| Loop round | Key `run:<label>:round:<n>`; type `weksa.loop_round` with spec version, profile revisions, model ids and prompt digests, sampled train items, Validation means and refusal counts, the digest of the inventory file it was scored under and, for a cycle's candidate round, its cycle `k` | Scored and recorded whole; immutable. A candidate round is put in one batch with its Decision. Lives in the run store on Yggdrasil | `run::round` and `run::cycle` (both through `score_round`) |
-| Loop decision | Key `run:<label>:cycle:<k>`; type `weksa.loop_decision` with the base round and revision, the edit prompt's digest and Train keys, the editor's answer digest, the candidate revision, inventory digest and round, the base, candidate and floor readings (chrF, meaning, composite), the threshold and the verdict (Accepted, or Rejected for edit-parse, edit-admit, no-gain, regressed chrF or meaning); digests and numbers, no text | Immutable. The latest Accepted one names the run's head inventory (`<root>/cycle-<k>/inventory.cc`, its candidate digest, its candidate round); with none the head is the copy `create` made at `<root>/inventory.cc`. Lives in the run store on Yggdrasil | `run::cycle`'s accept rule, `run::decide`: the validation composite gains more than max(noise floor, `LADDER_STEP`) and no metric falls past max(its floor, one step), differences compared in billionths so a gain of exactly one step is a tie |
+| Loop round | Key `run:<label>:round:<n>`; type `weksa.loop_round` with spec version, profile revisions, model ids and prompt digests, sampled train items, Validation means and refusal counts (from cut `ja-panel-loop`: one set per language of the run's panel, no pooled mean), the digest of the inventory file it was scored under and, for a cycle's candidate round, its cycle `k` | Scored and recorded whole; immutable. A candidate round is put in one batch with its Decision. Lives in the run store on Yggdrasil | `run::round` and `run::cycle` (both through `score_round`) |
+| Loop decision | Key `run:<label>:cycle:<k>`; type `weksa.loop_decision` with the base round and revision, the edit prompt's digest and Train keys, the editor's answer digest, the candidate revision, inventory digest and round, the base, candidate and floor readings (chrF, meaning, composite), the threshold and the verdict (Accepted, or Rejected for edit-parse, edit-admit, no-gain, regressed chrF, meaning or composite); digests and numbers, no text | Immutable. The latest Accepted one names the run's head inventory (`<root>/cycle-<k>/inventory.cc`, its candidate digest, its candidate round); with none the head is the copy `create` made at `<root>/inventory.cc`. Lives in the run store on Yggdrasil | `run::cycle`'s accept rule, `run::decide`: the validation composite gains more than max(noise floor, `LADDER_STEP`), no metric falls past max(its floor, one step), the composite does not fall past max(its floor, one step), and a non-finite reading rejects (the one regression test, `run::regression`); differences compared in billionths so a gain of exactly one step is a tie. From cut `ja-panel-loop` the readings, floor and threshold are kept per panel language and `run::regression` runs per language and is the one regression test (`decide` adds the gain test for a one-language panel): any language regressing rejects (verdicts `regressed-chrf`, `regressed-meaning`, `regressed-composite`), otherwise a one-language panel accepts as `decide` does and a panel of two or more accepts when the sum of composite deltas exceeds one `LADDER_STEP` (billionths). Given up: strict Pareto non-regression; a language may lose up to its own noise floor if the panel nets more than a step, because zero tolerance ratchets every base to a favourable noise draw and strangles the loop. Termination: each accept raises the composite sum by more than a step and composites lie in -0.5 to 1, so a run accepts at most 1.5 * languages / `LADDER_STEP` edits |
 | Score | Key `<lowering-key>:<metric>@<metric-version>`; type `weksa.score` | Immutable; a new metric version scores again under a new key | The scorer, deterministic given the metric version and the embedder's model id. Cut `scorer` computes scores as values; cut `golf-loop-en` stores them, because the lowering keys they hang from arrive with the loop. Lands with follow-up `golf-loop-score-docs`, in the round's directory; nothing in the cycle reads them |
 | Lowering trace | Key `lowering:<packet-key>:<profile>@<rev>:<lowerer-digest>:<sample>`; type `weksa.lowering` holding the surface text and its trace together | Immutable. A surface text cannot exist without its trace, because they are one record (`lowering-traced`) | The lowerer emits; the lowerer sees the packet without its `trace` (the input type has no such field), never the corpus item |
 | Conlang lexicon entry | Key `lex:<language>:<concept-id>`; root form, morphology class | Root placed at its concept's embedding when the concept first needs a form in that language; stable once accepted; diachrony derives later forms, it does not overwrite | The language project's owner: the operator for her settings' languages, the loop proposing roots for her review |
@@ -411,7 +411,7 @@ One line per cut; specs exist for the cuts about to run (2d and 4, siblings on `
 7d. `golf-loop-model-lowerer` (spec r1; branch `weksa-lowering/golf-loop-model-lowerer`): the round lowers through the `ModelPort`. `Prompt::lower` (`context.rs`) takes a `LoweringInput` (no text, key, group or speaker getter), the inventory at the view's revision and the en-US entity forms, and prints `LOWER_INSTRUCTIONS`, the meaning of the packet, the entities line and the inventory listing; the item key goes only to `item_keys`. The answer is `{"text"}`, read as `LoweringDraft` in `encode.rs`, held in `score_round`'s locals and scored once; it is never put in `run.cc`, a `RoundRecord`, a `Decision` or `EditFeedback`. A round has two answer phases (every encode prompt, then every lowering prompt), all or nothing: while any prompt is unanswered `packets.cc` is discarded and nothing reaches `run.cc`. `lower::lower` and the template table leave the loop (they remain `weksa lower`'s; follow-up `table-retirement`), so an entry an edit adds can be said and a cycle can buy a gain. One source pin remains: `PROMPT_SOURCE_DIGEST` covers `context.rs`, `split.rs` and `lower.rs` (`RunRecord` key 7 and `RoundRecord` key 3 are retired). The run's record pins `LowererReach` (`weksa loop open --lowerer-reach briefed-subagent|tool-less-relay`, `RunRecord` key 12) and every printed round and cycle line says it; a briefed-subagent run says its numbers are smoke-round only (rulings `lowerer-call-reach-toolless-relay`, `dao-round-seed-inventory`). A lowering is refused at `Lower` when blank, over `MAX_LOWERING_BYTES` (4096) or holding a control character other than a line break or tab; `PROMPT_SOURCE_DIGEST` also covers `packet.rs`. Not here: per-item lowering text documents (`golf-loop-score-docs`), the subprocess adapter. Waits on 7c.
 7. `golf-loop-en` (7b and 7c landed the round, `ModelPort`, encoder prompt, template digest, round records and the edit-accept cycle; the rest remains): the packet store bound to one inventory store everywhere (`packet-store-inventory-binding`), a subprocess adapter, Score documents, `weksa score` in the loop, the detached unit on Yggdrasil. Waits on 3, 5, 6 and follow-up `claude-on-yggdrasil`.
 8. `style-axis`: a style-embedding score behind the scorer port. Waits on 3.
-9. `ja-panel`: ja-JP into the loop's panel. Waits on 7.
+9. `ja-panel`: ja-JP into the loop's panel, in two cuts on `e9cbd9b`. 9a `ja-panel-loop` (spec r1): language is the item's and the panel the run's: `Prompt::lower` takes the item's language and prints it on a language line (no prompt names English), entity forms are read in that language, `RunRecord` pins the panel (`weksa loop open --panel`), offers, mint and recall read only panel items, round means, floors and readings are per panel language, the accept rule runs `decide` per language, the recall split works on unspaced scripts, and `weksa corpus add` has no default language. 9b `ja-panel-corpus` (spec r1, after 9a): the ja-JP slice of `data/original`, model-written Japanese Train and Validation passages and eight Aozora Bunko public-domain Test sentences with full provenance, and their entities. Cut 5 is not a prerequisite: neither language lowers with ontology entries until cut 5 gives both theirs.
 10. `conlang-lexicon`: the first conlang's lexicon placed at concept embeddings, its morphology data, its ontology entries and the gloss reader. Waits on 3, 5 and question `first-conlang`.
 11. `convergence-freeze`: the convergence test, `Checkpoint`'s one door (built from the convergence window over the persisted round records), the freeze, the re-encode into training pairs. Waits on 7, 9 and 10.
 12. `distil`: fine-tune a lowerer on the frozen training set. Waits on 11 and a host question asked then.
diff --git a/schemas/cultnet/weksa.loop_decision.schema.json b/schemas/cultnet/weksa.loop_decision.schema.json
index 0966600..b3266f0 100644
--- a/schemas/cultnet/weksa.loop_decision.schema.json
+++ b/schemas/cultnet/weksa.loop_decision.schema.json
@@ -1,12 +1,9 @@
 {
   "$schema": "https://json-schema.org/draft/2020-12/schema",
   "title": "Decision",
-  "description": "One closed edit-accept cycle: digests and numbers, no text. Key\n`run:<label>:cycle:<k>`. Only [`cycle`] builds one.\n\n```\nfn f(d: &weksa::run::Decision) -> u32 { d.k() }\n```\n\nEvery field is given, so the literal below fails only on privacy; its twin is\nthe same literal in the unit test `a_decision_literal_compiles_in_the_lib`.\n\n```compile_fail,E0451\nuse weksa::run::{Call, Decision, Reading, Verdict};\nfn f() -> Decision {\n    let r = Reading { chrf: 0.0, meaning: 0.0, composite: 0.0 };\n    Decision {\n        k: 1,\n        base_round: 1,\n        base_rev: 1,\n        base_inventory_digest: String::new(),\n        edit: Call { prompt: String::new(), items: vec![] },\n        edit_answer_digest: None,\n        candidate_rev: None,\n        candidate_inventory_digest: None,\n        candidate_round: None,\n        base: r,\n        candidate: None,\n        floor: r,\n        threshold: 0.0,\n        verdict: Verdict::Accepted,\n    }\n}\n```",
+  "description": "One closed edit-accept cycle: digests and numbers, no text. Key\n`run:<label>:cycle:<k>`. Only [`cycle`] builds one.\n\n```\nfn f(d: &weksa::run::Decision) -> u32 { d.k() }\n```\n\nEvery field is given, so the literal below fails only on privacy; its twin is\nthe same literal in the unit test `a_decision_literal_compiles_in_the_lib`.\n\n```compile_fail,E0451\nuse weksa::run::{Call, Decision, Verdict};\nfn f() -> Decision {\n    Decision {\n        k: 1,\n        base_round: 1,\n        base_rev: 1,\n        base_inventory_digest: String::new(),\n        edit: Call { prompt: String::new(), items: vec![] },\n        edit_answer_digest: None,\n        candidate_rev: None,\n        candidate_inventory_digest: None,\n        candidate_round: None,\n        panel: vec![],\n        verdict: Verdict::Accepted,\n    }\n}\n```",
   "type": "object",
   "properties": {
-    "base": {
-      "$ref": "#/$defs/Reading"
-    },
     "base_inventory_digest": {
       "type": "string"
     },
@@ -21,16 +18,6 @@
       "format": "uint32",
       "minimum": 0
     },
-    "candidate": {
-      "anyOf": [
-        {
-          "$ref": "#/$defs/Reading"
-        },
-        {
-          "type": "null"
-        }
-      ]
-    },
     "candidate_inventory_digest": {
       "type": [
         "string",
@@ -64,17 +51,17 @@
         "null"
       ]
     },
-    "floor": {
-      "$ref": "#/$defs/Reading"
-    },
     "k": {
       "type": "integer",
       "format": "uint32",
       "minimum": 0
     },
-    "threshold": {
-      "type": "number",
-      "format": "double"
+    "panel": {
+      "description": "One row per panel language, in panel order.",
+      "type": "array",
+      "items": {
+        "$ref": "#/$defs/PanelReading"
+      }
     },
     "verdict": {
       "$ref": "#/$defs/Verdict"
@@ -86,10 +73,8 @@
     "base_rev",
     "base_inventory_digest",
     "edit",
-    "base",
-    "floor",
-    "threshold",
-    "verdict"
+    "verdict",
+    "panel"
   ],
   "$defs": {
     "Call": {
@@ -113,10 +98,54 @@
     },
     "Metric": {
       "description": "Which metric an edit regressed.",
-      "type": "string",
-      "enum": [
-        "Chrf",
-        "Meaning"
+      "oneOf": [
+        {
+          "type": "string",
+          "enum": [
+            "Chrf",
+            "Meaning"
+          ]
+        },
+        {
+          "description": "The composite fell, or a reading was not a finite number.",
+          "type": "string",
+          "const": "Composite"
+        }
+      ]
+    },
+    "PanelReading": {
+      "description": "One panel language's row of a cycle: the head's Validation reading, the\ncandidate's (none when the edit never reached a round), the language's\nmeasured floor and the threshold derived from it. The threshold decides only\nin a one-language panel ([`decide`]); with two or more languages it is\nrecorded beside the floor and the accept is the sum rule of\n[`decide_panel`].",
+      "type": "object",
+      "properties": {
+        "base": {
+          "$ref": "#/$defs/Reading"
+        },
+        "candidate": {
+          "anyOf": [
+            {
+              "$ref": "#/$defs/Reading"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        },
+        "floor": {
+          "$ref": "#/$defs/Reading"
+        },
+        "language": {
+          "type": "string"
+        },
+        "threshold": {
+          "type": "number",
+          "format": "double"
+        }
+      },
+      "required": [
+        "language",
+        "base",
+        "floor",
+        "threshold"
       ]
     },
     "Reading": {
diff --git a/schemas/cultnet/weksa.loop_round.schema.json b/schemas/cultnet/weksa.loop_round.schema.json
index 4117573..a9e79df 100644
--- a/schemas/cultnet/weksa.loop_round.schema.json
+++ b/schemas/cultnet/weksa.loop_round.schema.json
@@ -1,7 +1,7 @@
 {
   "$schema": "https://json-schema.org/draft/2020-12/schema",
   "title": "RoundRecord",
-  "description": "One scored round. It holds no text and no Test reading: per-item rows for\nTrain only, Validation only as means and refusal counts by stage. Only\n`run::round` builds one.\n\n```\nfn f(r: &weksa::run::RoundRecord) -> u32 { r.n() }\n```\n\nEvery field is given, so the literal below fails only on privacy; its twin\nis the same literal in the unit test `a_round_record_literal_compiles_in_the_lib`.\n\n```compile_fail,E0451\nuse weksa::run::{RefusalCounts, RoundRecord};\nuse weksa::score::SplitMean;\nfn f() -> RoundRecord {\n    RoundRecord {\n        n: 1,\n        inventory_rev: 1,\n        prompt_digest: String::new(),\n        corpus_digest: String::new(),\n        entity_digest: String::new(),\n        model: String::new(),\n        embedder: String::new(),\n        chrf_version: String::new(),\n        calls: vec![],\n        train: vec![],\n        train_mean: SplitMean::default(),\n        train_scored: 0,\n        validation_mean: SplitMean::default(),\n        validation_scored: 0,\n        validation_refused: RefusalCounts::default(),\n        inventory_digest: String::new(),\n        cycle: None,\n        admit_rules: vec![],\n        parse_reasons: vec![],\n        own_family: 0,\n    }\n}\n```",
+  "description": "One scored round. It holds no text and no Test reading: per-item rows for\nTrain only, Validation only as means and refusal counts by stage. Only\n`run::round` builds one.\n\n```\nfn f(r: &weksa::run::RoundRecord) -> u32 { r.n() }\n```\n\nEvery field is given, so the literal below fails only on privacy; its twin\nis the same literal in the unit test `a_round_record_literal_compiles_in_the_lib`.\n\n```compile_fail,E0451\nuse weksa::run::RoundRecord;\nfn f() -> RoundRecord {\n    RoundRecord {\n        n: 1,\n        inventory_rev: 1,\n        prompt_digest: String::new(),\n        corpus_digest: String::new(),\n        entity_digest: String::new(),\n        model: String::new(),\n        embedder: String::new(),\n        chrf_version: String::new(),\n        calls: vec![],\n        train: vec![],\n        inventory_digest: String::new(),\n        cycle: None,\n        admit_rules: vec![],\n        parse_reasons: vec![],\n        own_family: 0,\n        languages: vec![],\n    }\n}\n```",
   "type": "object",
   "properties": {
     "admit_rules": {
@@ -49,6 +49,13 @@
       "format": "uint32",
       "minimum": 0
     },
+    "languages": {
+      "description": "One reading per panel language, in panel order. No pooled mean exists.",
+      "type": "array",
+      "items": {
+        "$ref": "#/$defs/LanguageRound"
+      }
+    },
     "model": {
       "type": "string"
     },
@@ -80,27 +87,6 @@
       "items": {
         "$ref": "#/$defs/TrainRow"
       }
-    },
-    "train_mean": {
-      "$ref": "#/$defs/SplitMean"
-    },
-    "train_scored": {
-      "description": "Train items that lowered and scored; `train_mean` is over all of them\nand counts a refused item as 0.",
-      "type": "integer",
-      "format": "uint32",
-      "minimum": 0
-    },
-    "validation_mean": {
-      "$ref": "#/$defs/SplitMean"
-    },
-    "validation_refused": {
-      "$ref": "#/$defs/RefusalCounts"
-    },
-    "validation_scored": {
-      "description": "Validation items that lowered and scored; `validation_mean` is over all\nof them and counts a refused item as 0, so refusing a weak item cannot\nraise it.",
-      "type": "integer",
-      "format": "uint32",
-      "minimum": 0
     }
   },
   "required": [
@@ -114,12 +100,8 @@
     "chrf_version",
     "calls",
     "train",
-    "train_mean",
-    "validation_mean",
-    "validation_refused",
-    "train_scored",
-    "validation_scored",
-    "inventory_digest"
+    "inventory_digest",
+    "languages"
   ],
   "$defs": {
     "Call": {
@@ -141,6 +123,44 @@
         "items"
       ]
     },
+    "LanguageRound": {
+      "description": "One panel language's readings in a round: the means over that language's\nitems only (a refused item counts 0) and how many items lowered and scored.",
+      "type": "object",
+      "properties": {
+        "language": {
+          "type": "string"
+        },
+        "train_mean": {
+          "$ref": "#/$defs/SplitMean"
+        },
+        "train_scored": {
+          "description": "Train items that lowered and scored; `train_mean` is over all of them.",
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0
+        },
+        "validation_mean": {
+          "$ref": "#/$defs/SplitMean"
+        },
+        "validation_refused": {
+          "$ref": "#/$defs/RefusalCounts"
+        },
+        "validation_scored": {
+          "description": "Validation items that lowered and scored; `validation_mean` is over all\nof them and counts a refused item as 0, so refusing a weak item cannot\nraise it.",
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0
+        }
+      },
+      "required": [
+        "language",
+        "train_mean",
+        "train_scored",
+        "validation_mean",
+        "validation_scored",
+        "validation_refused"
+      ]
+    },
     "Outcome": {
       "oneOf": [
         {
diff --git a/schemas/cultnet/weksa.loop_run.schema.json b/schemas/cultnet/weksa.loop_run.schema.json
index b339def..bb63827 100644
--- a/schemas/cultnet/weksa.loop_run.schema.json
+++ b/schemas/cultnet/weksa.loop_run.schema.json
@@ -49,6 +49,13 @@
       "description": "The answering model.",
       "type": "string"
     },
+    "panel": {
+      "description": "The languages the run offers, reads and decides on: BCP 47-form tags,\nsorted, unique, at least one, set once at open. An item of any other\nlanguage is never offered, minted from, probed or scored.",
+      "type": "array",
+      "items": {
+        "type": "string"
+      }
+    },
     "prompt_digest": {
       "type": "string"
     }
@@ -65,7 +72,8 @@
     "embedder",
     "chrf_version",
     "inventory_digest",
-    "lowerer_reach"
+    "lowerer_reach",
+    "panel"
   ],
   "$defs": {
     "LowererReach": {