diff --git a/tests/vectors/numeric-leaves/README.md b/tests/vectors/numeric-leaves/README.md
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+# numeric-leaves vectors
+
+Written only by the C# reference, `tests/GameCult.Caching.Tests/NumericLeafVectorTests.cs`, with
+`CULTCACHE_WRITE_VECTORS=1`. Every other run reads these files and compares them byte for byte; a changed vector is a
+reviewed commit. Other runtimes decode them and are held to the same answers.
+
+A document with one slot, `[value]`, whose slot is a C# `int`, `long`, `float` or `double` (leaf `int32`, `int64`,
+`float32`, `float64`).
+
+- `reads.msgpack`: an array of `[leaf, payload, accepted, bits]`. `payload` (bin) is the one-slot record fed to the
+  reference; `accepted` is whether it read; `bits` (bin, 8 bytes, big-endian) is the int64 it read, or the IEEE bits of
+  the double it read (a float32 widened), and empty when refused. Every value is fed to every leaf.
+- `writes.msgpack`: an array of `[leaf, text, bytes]`. `text` is a decimal for an integer leaf and the double's IEEE
+  bits in hex for a float leaf; `bytes` (bin) is the one-slot record the reference writes for that value.
diff --git a/tests/vectors/numeric-leaves/mixed-record.msgpack b/tests/vectors/numeric-leaves/mixed-record.msgpack
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diff --git a/tests/vectors/numeric-leaves/writes.msgpack b/tests/vectors/numeric-leaves/writes.msgpack
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