Use with 'instance of' (P31) for wiki categories that define a set of articles defined by a set of common types and properties. (e.g. 'Planetary scientists' (Q8764963), 'Films set in the 1660s' (Q25308979), etc.). Criterion for membership should be defined either with 'category contains' (P4224) and or ''(P3921). In either case these predicates should be defined to the most specific scope possible. E.g. "contains humans who have occupation planetary scientist" should be preferred over simply "contains human". (anglais)