The citation gate checks tag SHAPE, never tag REALITY: a well-formed invented token passes exactly as a genuine one does, and reads to a human as a real citation

Successor to TERRA-67, filed on audit-terra-ca own not-exercised list rather than on a new premise. TERRA-67 measured that the gate REJECTS unverifiable prose - that hole does not exist. This is what the same measurement exposed. MEASURED ACCEPTANCE (audit-terra-ca msx184xgkj0h): the gate accepts a tag-shaped string, agent-cc or -ca followed by 12 lowercase alphanumerics. It does NOT check that the tag was ever sent, that it resolves, that it is scoped to the revision being pushed, or that it is non-superseded. Audit named all four as not exercised. WHY THIS IS NOT THEORETICAL AND NOT ABOUT MALICE. These are cooperating agents; the realistic failure is an agent citing a tag it half-remembers, mistypes, or carries across from another thread. Both instances already exist on terra: terra_27 carried a REAL tag that was SUPERSEDED and a presence check passes it (TERRA-64); and pm-terra-cc asserted from memory that a clean file cited a dead GO, filing a WI on it. A shape check passes both. Worse than the prose case it replaces - prose at least looks like prose to a human reader, while a well-formed 12-char token reads as a genuine citation. MEASUREMENT FIRST, DO NOT DESIGN THE FIX. Establish what is checkable from where the gate actually runs (the pushing host, inside .gitpush-pre.sh). Hub-side tag verification may be reachable from there; that is a measurement, not an assumption. Coder-terra-cc owns any change to scripts/check-migration-citations.sh afterwards - they own the script. BOUND, and report which one you answered: EXISTENCE (was this tag ever sent, does it resolve) is a different and easier question than CURRENCY AND SCOPE (was this GO issued for THIS revision, has it been superseded). Currency may not be mechanically answerable at all. Existence alone would still be a real narrowing and is a legitimate stopping point - but it must be stated as existence-only, never reported as if it settled currency. ALSO STILL UNEXERCISED from TERRA-67 and carried here so it is not lost: the wired .gitpush-pre.sh CHANGED handoff has never been exercised on a real push, and the declared NO TAG: exception has never been tested.