A frame for reading archives that span a vocabulary-shift. Distinguishes *topic-change* (a person took up a new subject) from *topic-completion* (a person was already doing the practice; the new vocabulary named it). Includes the Sonnet test for distinguishing phase-transition from retroactive renarration. Use when reading any archive where a new vocabulary feels like a discovery; useful for biographical archives, research corpora, and personal-development records.
