On 19.10.2015 04:44, Emw wrote: ...
The phrase "is a" is in no way mutually exclusive with "subclass of". "Is a" is ambiguous -- it can mean the subject is either a class or an instance. In other words, "is a" can mean either /instance of/ (P31) or /subclass of/ (P279).
Indeed. Alas, some languages on Wikidata use the literal translation of "is a" as a label for "instance of". German is among them.
Markus