I'm reading up on MDX for work, specifically with respect to Microsoft SQL Server and Analysis Services. I just wanted to post a quote from MDX Solutions with Microsoft SQL Server Analysis Services and then not comment on it any further.

Tip: Although it won't occur in every database, it is possible (in Analysis Services) for two members in a dimension to have exactly the same unique name... If you query for a member using it's "unique" name that is not unique, all the members that share that unique name will be returned. The key-based naming ... can be used to avoid this happening.

In MDX a unique name is an automatically generated identifying attribute of an entity. Apparantely Microsoft failed to understand this entirely.