diff --git a/CLAUDE.md b/CLAUDE.md
index 2e77c0a..cf4a939 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -12,6 +12,7 @@ docs it indexes.
 3. `DECISIONS.md` — the ADRs. Decisions are settled here; do not re-litigate without a new ADR.
 4. `docs/architecture/architecture.md`, `docs/data-model.md`, `docs/use-cases/*.feature`.
 5. `docs/homelab-integration.md` — the concrete endpoints/conventions you'll need.
+6. `LANGUAGE.md` — the project vocabulary. Apply the caveman rubric before destructive operations.
 
 ## How to work in this repo