tpope/vim-fugitive — pull request #500 by idanarye (2014-06-12 12:18:21+00:00)
Title: Add the :Gtag command for tag creation

:Gtag is for tag creation only - tag listing and tag deletion is
blocked. Since these commands don't require a message, they should be
used with :Git.

The tag message buffer uses the gitcommit filetype since any ftplugin
that helps in writing commit messages and targets the gitcommit buffer
will probably be useful for writing tag messages as well.