diff --git a/.claude/rules/vocabulary.md b/.claude/rules/vocabulary.md
new file mode 100644
index 0000000..d0fbb64
--- /dev/null
+++ b/.claude/rules/vocabulary.md
@@ -0,0 +1,34 @@
+## Vocabulary
+
+From `the-custodian/docs/agent-environment-orientation.md` §8 (SecurityCanon
+Mode of Authority). It is a writing rule for *our own* prose, not a
+find-and-replace over the canon.
+
+**Never write bare "operator" for Bernd.** `Operator` is a CARING lifecycle
+role and `OPERATE` is an Auth Mode, so the word is already taken. Bernd is
+**the founder**, and a decision of his is the founder exercising
+`GOVERN @ estate`. Write "authorized by the founder (`GOVERN @ estate`) on
+<date>", not "authorized by the operator".
+
+Applies to workplans, demand and feedback steward notes, assimilation records,
+decision records, commit messages and messages to other agents.
+
+**These uses of "operator" are correct — do not "fix" them:**
+
+- the CARING canonical role `Operator` and every derivative (`Vendor
+  Operator`, `RuntimeOperator`, CRS-009 Operator separation);
+- domain prose about the people or software that run systems: "network
+  owners, operators, stewards", "operator confirmation", Kubernetes operators;
+- units of labour, e.g. "operator hours", which arrived from consumers as
+  economic evidence.
+
+**Do not edit these files to change wording at all:** `seeds/`,
+`infospace/assimilation/*/source/`, `history/`, and consumer-authored feedback
+bodies (steward notes are the place for our words). They are provenance.
+
+`AGENTS.md` is generated from state-hub templates and its wording is fleet-wide.
+Report a violation there to `the-custodian`; do not patch our copy, which
+diverges and is reverted on the next regeneration.
+
+Also: `GOVERN`, `ADMINISTER`, `CONSTRUCT` and the rest are modes, not a
+privilege ladder, and `BREAK_GLASS` is an activation, not a mode.
diff --git a/CLAUDE.md b/CLAUDE.md
index 7d7672c..ae1f3b9 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -8,5 +8,6 @@
 @.claude/rules/stack-and-commands.md
 @.claude/rules/architecture.md
 @.claude/rules/repo-boundary.md
+@.claude/rules/vocabulary.md
 @.claude/rules/credential-routing.md
 @.claude/rules/agents.md