Good catch on those duplicate categories![change source]
Thanks for finding those duplicate categories (file formats and American musical theater actors). I went ahead and merged them and put category redirect tags on them. With the redirect tags, if anyone tries to save a page using those categories, it will automatically change them to the correct category.
For future reference, that kind of change doesn't necessarily need an RfD. Anyone can move articles from one category to another and put a category redirect on the category being emptied. If you find more of these and would like help moving articles, feel free to let me know because I can use AWB to do it. Cheers! --Auntof6 (talk) 18:18, 27 April 2014 (UTC)