There are two closely related tags, numbers and numerals, which don't have a tag excerpt or wiki, and many questions have both these tags. Would it make sense to synonymize them, just like our sister sites English Language & Usage, English Language Learners and German Language?
Judging by the existing questions with these tags, I would consider them identical. I would be happy to merge them, but I will wait a bit and see if others consider it a good idea too.
There is also the concept of grammatical number (singular or plural, rarely dual), but perhaps that is best captured with the three tags for those numbers. Anyone is free to write a tag description/excerpt, and help with that is always much appreciated. I doubt a wiki would be read much, but I have nothing against it if someone wants to write more details.