Two readings were on record and both were wrong in different directions: the
structure doc called it "normal state -> focused state" from a single example,
and the backlog called it "refuted as focus; unexplained otherwise".
Classified every link reachable from a declaration table: 1467 links, and ALL
1467 resolve to a RATC child of their own bundle, ALL are .rat -> .rat, none
dangle and none self-link. 1076 (73%) match the <stem>f focus pattern; the other
391 are chains between effect records - px_bunk_eff01 -> pjex_eff -> pjex_eff07,
pveff01 -> pjeff02 -> pjeff21 - which also explains why only 227 targets are
themselves declared elements: the middle of a chain is, the end is not.
So `opt ` is a record-to-record reference within the bundle, and focus is its
commonest use rather than its meaning.
Coverage is stated rather than glossed: the bundles hold 18718 raw `opt ` tags
against the 1467 classified, because opt_link reads the first tag of a DECLARED
element's record. Roughly 92% of occurrences sit deeper in the chains (or are
byte coincidences - the scan is unaligned) and are untested. The numbers are
asserted so the answer cannot drift back into an anecdote.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PMRJjbxLqZtsb5Vb7KunPE
e9befb2545