A documentation system where drawing notes reference a numbered code from a master keynote list (often tied to a classification system like MasterFormat) instead of writing free text directly on every sheet. A tag on a drawing shows just the code; the full note text lives in one central, editable list, so correcting a note's wording once updates it everywhere that keynote appears across the entire project.

It is essentially the annotation-level equivalent of shared parameters: one authoritative source of text, referenced everywhere, instead of the same phrase retyped independently on forty different sheets with forty chances to go slightly out of sync.