Have we considered separating in some way (in the UI, and possibly the data model) properties which track identifiers in external databases vs. properties that describe the item using Wikidata-internal links? As more and more external identifiers are added, it's easy to get lost in them while looking for the right property to describe an item.

We're effectively already doing this with Wikimedia identifiers by calling them "sitelinks" and it seems like a potential logical extension of that concept to group other kinds of external identifiers in their own section rather than having CANTIC, BIBSYS identifiers, Freebase identifiers or even DMOZ links mixed together with the primary descriptors of an author or work, for example.

Thanks,

Erik