UML22 — Section: 9.3.11 p 182

All rolenames in non-navigable associations in the UML metamodel should be stated, to allow reaching from one element of the association to the other using OCL. Currently, this is limited to un-ambigous type names if the rolename is not stated. For example, in section "9.3.11 Port (from Ports)", Port has required and provided interfaces, and has no rolename on both associations. There is no current way, using OCL, of getting from one Interface to a Port that provides or requires it, as "self.port" is ambigous because it doesn't specify if the programmer is looking for Ports providing or requiring such Interface. The situation repeats in many other associations.

Discussion: It is not required for the specification to name such associations. Navigation is not that hard if this is really desired: find all ports and select the subset that has the appropriate interface. Also, OCL is not constrained by navigability. Discussion: Closed, no change