Last modified: 2012-11-20 05:55:31 UTC
SMW does not recognize "Category:+" as a wildcard, which is inconsistent with the rest of the way SMW operates. Apparently, it's a special case that needs to be recognized, apart from interpreting "+" as a category. https://bugzilla.wikimedia.org/show_bug.cgi?id=29891#c2 ...the reason that [[Category:+]] does not work is simply that it is ambiguous with SMW's way of searching for pages in the category called "+". Since this is not a valid page, the query ends up having no conditions and all pages are returned.
Is there any use case for querying for pages that have some arbitrary category without saying which category it is? I do not really see what useful information the resulting list of pages could give you, unless you use categories only in a very limited sense (and ensure that all other users do the same).
At the time I posted this bug report, I think what I was trying to do was find uncategorized pages that also matched some specific semantic query. I might have also been trying to organize categories using their own "meta" semantic data.
