It is ridiculous that since we prefixed tag names to our page titles, the title no longer begins with a capital letter as it should according to the grammar of the English language. Tag badges differ from "normal" badges in this way as well.
Tag wiki editors should be able to specify the preferred capitalization/punctuation of a tag when it is shown in such places as page titles. It need not affect the display of the tag listing for a question, just specific places such as the title bar and the names of tag badges.
If it is a concern, we could restrict such changes to those of capitalization or punctuation. That is, the new title, with spaces replaced by hyphens, should normalize to the usual tag name.