My only concern is that tags make me think of Twitter. They have prolific tagging but don't use it to form a category system. We already have categories for people, prayer, and stained glass. It seems that you really want a page that lets you view the contents of not just one category, but from multiple categories connected with "and", "or", and "not".
> Date: Thu, 9 May 2013 12:05:02 +0200
> From: jane023@gmail.com
> To: wikidata-l@lists.wikimedia.org
> Subject: Re: [Wikidata-l] Question about wikipedia categories.
>
> I think it is a perfectly good and noble ambition to strive for "a
> logically sound ontology as contrasted with a controlled terminology".
> I just don't believe it is attainable. Perhaps you could build it by
> including all existing non-compatible ontologies. I had an interesting
> conversation about tagging last month, in which it was stated that
> enough tagging could cause new ontologies to appear through organic
> growth. I find that an interesting concept. Our Wikipedia category
> tree structures are being built vertically and horizontally around a
> few main categories like "Category:People" that slowly get split off
> into subcategories such as "Category:People praying on stained glass
> windows" as they get too large, whereas a tagging system could lead to
> the formation of new categories for which there is no parent category
> (as yet).