Am 08.07.2015 um 14:13 schrieb John Erling Blad:
What you want is closer to a redirect than an alias, while an alias is closer to a disambiguation page.
Yes. The semantics of labels on properties is indeed different from labels on items, and always has been. Property labels are defined to be unique names. Extending the uniqueness to aliases allows them, to qact as redirects, which allow use to "rename" or "move" properties (that is, change their label).
Using (unique) aliases for this seems the simplest solution. Introducing another kind-of-aliases would be confusing in the UI as well as in the data model, and wopuld require a lot more code, which is nearly exactly the same as for aliases.
I don't follow your example with the DC vocabulary. For the height, width and length properties, why would one want an alias that is the same for all of them? What would that be useful for?