Merge pull request #4078 from handrews/dup-op-304

Further clarify link operation ambiguity (3.0.4)

versions/3.0.4.md

@@ -2310,9 +2310,10 @@ For computing links and providing instructions to execute them, a [runtime expre
 This object MAY be extended with [Specification Extensions](#specification-extensions).
 
 A linked operation MUST be identified using either an `operationRef` or `operationId`.
-In the case of an `operationId`, it MUST be unique and resolved in the scope of the OpenAPI description.
-Because of the potential for name clashes, the `operationRef` syntax is preferred
-for multi-document OpenAPI descriptions.
+The identified or reference operation MUST be unique, and in the case of an `operationId`, it MUST be resolved within the scope of the OpenAPI Description (OAD).
+Because of the potential for name clashes, the `operationRef` syntax is preferred for multi-document OADs.
+However, because use of an operation depends on its URL path template in the [Paths Object](#paths-object), operations from any [Path Item Object](#path-item-object) that is referenced multiple times within the OAD cannot be resolved unambiguously.
+In such ambiguous cases, the resulting behavior is implementation-defined and MAY result in an error.
 
 Note that it is not possible to provide a constant value to `parameters` that matches the syntax of a runtime expression.
 It is possible to have ambiguous parameter names, e.g. `name: "id", in: "path"` and `name: "path.id", in: "query"`; this is NOT RECOMMENDED and the behavior is implementation-defined, however implementations SHOULD prefer the qualified interpretation (`path.id` as a path parameter), as the names can always be qualified to disambiguate them (e.g. using `query.path.id` for the query parameter).