BPMN21 — Underspecification of ChoreographyLoopType

The loop types of choreography activities do not provide any information about: (1) the "hard-coded" cardinality of the loop (how often is the loop repeated) or (2) the expression that must be evaluated during the choreography enactment based on the data contained in the messages exchanged up to that point during the enactment. In the latter case, specifying the expression is not enough: for reasons of enforceability, it should be possible to specified which participant(s) must evaluate the expression.