As summarized preliminarily here: - https://github.com/BuildingSync/TestSuite/pull/19#discussion_r470904792 The question comes down to: - What does a link between a 'System' and a Building or Section mean? - Do we just say: "Link to the lowest common denominator is what we expect?" I believe our approach from BSync perspective is we would just expect the lowest common denominator to be linked. @markborkum @nllong thoughts?