We expect Joe Public to be vague about technical terms (calling every cold a "flu" for example) but experts who do it are, what, pushing some dismissive/co-optive agenda? Indeed, it is the "tell" of an expert that they err on the side of precision for technical terminology.
Of course, a usage that people may understand on rdf-dev maillist may seem incorrect and unhelpful on xml-dev. If I joined a discussion group of anatomy professors, and insisted on using "duodenum" to mean the whole gastro-intestinal tract (because everyone knows that an upset stomach includes diasters lower down), and that the anatomists were wrong for having this strangely limited and non-holistic view, should it be regarded as helpful-to-communication or ...umm.. eccentric?
Cheers
Rick
