Source use and currentness

Each pattern records the sources that change its move, result, test, or return and states what those sources do not establish. Academic attention, institutional endorsement, press coverage, standardization, popularity of a label, and availability of an artifact do not by themselves show current practice, effectiveness, prevalence, transmission, or retention. When direct evidence is sparse, use an explicit expert estimate and its revision condition rather than fabricating a measurement programme.

Refresh only the affected pattern, relation, practical entry, or source use when a direct source changes, a new Music-or-Dance Method alters the recommended move, an FPF result used below changes, or representative reader and practitioner use reveals a costly omission. Reopen the pattern-language architecture only when that evidence changes a pattern identity, split or merge, material result relation, problem-family coverage, or product boundary.