Consider this question from the point-of-view of a visitor to a WordPress blog, and not as a WordPress blog admin who can edit those numerous PHP files.
How can I see a list of all the posts under a category and a tag? Not clear? Let me explain with an example:
I have two categories -- Social Media (social) and Web (web), and I have a tag Tips and Tricks (tips-and-tricks).
Consider that I use the tag frequently with posts under both categories. The question is, how can a visitor to my blog, check posts tagged "tips-and-tricks" and under "social" category?
I am looking for a solution similar to this:
http://example.com/feed/?cat=11,12 (which we use to combine rss feeds of multiple categories). Thanks.