So what would
you suggest? We could stop categories from being able to
show up in other categories - that would neatly abolish the hierarchy.
OTOH, many articles would end up with a ridiculous number of cats at
the top (currently kept in check by the rough rule that if it's in a
subcat, you don't put it in the cat as well).
No, what I meant is allow any arbitrary categorization scheme - sets can,
after all, be inside other sets (or more than one set). A "related to"
scheme rather than "is a". See "Continued" below