Provided by: git-man_1.9.1-1ubuntu0.10_all 

NAME
git-mktag - Creates a tag object
SYNOPSIS
git mktag < signature_file
DESCRIPTION
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.
TAG FORMAT
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.
GIT
Part of the git(1) suite
Git 1.9.1 11/27/2018 GIT-MKTAG(1)