The tags [matrix-analysis](http://mathoverflow.net/questions/tagged/matrix-analysis) (32 questions tagged) and [matrix-theory](http://mathoverflow.net/questions/tagged/matrix-theory) (18 questions) should probably be merged, unless there is a strong difference between them that I am not aware of (incidentally, there is also [matrices](http://mathoverflow.net/questions/tagged/matrices), 150 questions tagged).

The tag [matrix-inverse](http://mathoverflow.net/questions/tagged/matrix-inverse) (6 questions) seems overly specific and in my opinion it should be removed outright.