Documentation: consistently refer to check-ref-format

Change the <name> placeholder to <tagname> in the SYNOPSIS section of
git-tag documentation, and describe it in the OPTIONS section in a way
similar to how documentation for git-branch does.

Add SEE ALSO section to list the other documentation pages these two pages
refer to.

Signed-off-by: Nanako Shiraishi <nanako3@lavabit.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-branch.txt

@@ -209,6 +209,12 @@ but different purposes:
 - `--no-merged` is used to find branches which are candidates for merging
   into HEAD, since those branches are not fully contained by HEAD.
 
+SEE ALSO
+--------
+linkgit:git-check-ref-format[1],
+linkgit:git-fetch[1],
+linkgit:git-remote[1].
+
 Author
 ------
 Written by Linus Torvalds <torvalds@osdl.org> and Junio C Hamano <gitster@pobox.com>

Documentation/git-tag.txt

@@ -10,17 +10,15 @@ SYNOPSIS
 --------
 [verse]
 'git tag' [-a | -s | -u <key-id>] [-f] [-m <msg> | -F <file>]
-	<name> [<commit> | <object>]
-'git tag' -d <name>...
+	<tagname> [<commit> | <object>]
+'git tag' -d <tagname>...
 'git tag' [-n[<num>]] -l [--contains <commit>] [<pattern>]
-'git tag' -v <name>...
+'git tag' -v <tagname>...
 
 DESCRIPTION
 -----------
 
-Adds a 'tag' reference in `.git/refs/tags/`.  The tag <name> must pass
-linkgit:git-check-ref-format[1] which basicly means that control characters,
-space, ~, ^, :, ?, *, [ and \ are prohibited.
+Adds a tag reference in `.git/refs/tags/`.
 
 Unless `-f` is given, the tag must not yet exist in
 `.git/refs/tags/` directory.
@@ -88,6 +86,12 @@ OPTIONS
 	Implies `-a` if none of `-a`, `-s`, or `-u <key-id>`
 	is given.
 
+<tagname>::
+	The name of the tag to create, delete, or describe.
+	The new tag name must pass all checks defined by
+	linkgit:git-check-ref-format[1].  Some of these checks
+	may restrict the characters allowed in a tag name.
+
 CONFIGURATION
 -------------
 By default, 'git-tag' in sign-with-default mode (-s) will use your
@@ -252,6 +256,10 @@ $ GIT_COMMITTER_DATE="2006-10-02 10:31" git tag -s v1.0.1
 ------------
 
 
+SEE ALSO
+--------
+linkgit:git-check-ref-format[1].
+
 Author
 ------
 Written by Linus Torvalds <torvalds@osdl.org>,