How many global, persistent tags can you have with org-mode? I seem to have org-tag-alist with its fast tag selection maxed out at 26. Is that the limit for it, lower-case letters in the alphabet? I would like to have potentially hundreds of tags as tags seem to be vaguely the same as a book index. And I would like this large body of tags available globally. I see there is an org-tag-persistent-alist but how does this differ from the org-tag-alist? I suppose org-tag-persistent-alist can't have fast selection keys? I realize, of course, you can simply make up any symbol, place it within colons and there's your tag; but I'm looking for a way to have persistent global tags by the hundreds.