I really don't know what glitches there are and if its like a credits warp or something like that I get why its banned earthbound does the same thing with the debug menu but why call it Any% when no glitches are allowed why not just call it any% glitchless and have an any% category?

I'm two years late on this answer, but the short answer is because it's basically the only category anyone runs. It would be more accurate to say "no major glitches" than just "Any%", but there aren't really other categories with different glitch-rules for DQ3.

The Japanese community effectively dictates the rules for the SFC runs, because there are about a thousand J runners and about a dozen Western runners. The official name of the category is 通常ED（増殖禁止）, but I don't know any of those kanji or what "ED" stands for. Pretty sure it translates to something like "Beat the game (Bug Limit)". I think the board underneath the main board has different glitch rules but I don't know what the difference is, and there's only one time on that board.

You can see the J boards here: http://niconamarta.sakura.ne.jp/index.php?game=%E3%83%89%E3%83%A9%E3%82%B4%E3%83%B3%E3%82%AF%E3%82%A8%E3%82%B9%E3%83%88%EF%BC%93