Recently, there's been a nice thread on "Xtreme Punning". I quite like Pat Hayes description of the situation:
Conventions which everyone has to agree to use: which will never happen. Names are cheap, but agreement on names is not cheap, so the fewer names we can get away with the better. The datatype example in my earlier email is a good example, IMO: all three uses are quite natural, and I wouldn't want to have to remember to distinguish xsd:number from rdfs:numberMapping from owl:numberThing.
Names can be freely used in ANY logical syntactic role, without ANY restrictions. EVERY occurrence of a name denotes the same thing. ALL names denote both a class and a property (and in CL a function; and in IKL, a proposition. No doubt other ideas can be incorporated.) ANYTHING can be an instance. Hence, any two legal sentences
(ontologies) can be simply concatenated and the result is still legal (no checking to be done when merging graphs) and meaningful. And it all works very simply, with a simple uniform semantics, which one can quickly get used to.