Reads a tag contents on standard input and creates a tag object that can also be used to sign other objects.
The output is the new tag's <object> identifier.
A tag signature file has a very simple fixed format: four lines of
object <sha1> type <typename> tag <tagname> tagger <tagger>
followed by some optional free-form message (some tags created by older git may not have tagger line). The message, when exists, is separated by a blank line from the header. The message part may contain a signature that git itself doesn't care about, but that can be verified with gpg.
Written by Linus Torvalds <m[blue]torvalds@osdl.orgm[][1]>
Documentation by David Greaves, Junio C Hamano and the git-list <m[blue]git@vger.kernel.orgm[][2]>.
Part of the git(1) suite