Merge branch 'mm/keyid-docs' into maint

Very small number of options take a parameter that is optional
(which is not a great UI element as they can only appear at the end
of the command line).  Add notice to documentation of each and
every one of them.

* mm/keyid-docs:
  Documentation: explain optional arguments better
  Documentation/grep: fix documentation of -O
  Documentation: use 'keyid' consistently, not 'key-id'

Documentation/git-am.txt

@@ -141,7 +141,9 @@ default.   You can use `--no-utf8` to override this.
 
 -S[<keyid>]::
 --gpg-sign[=<keyid>]::
-	GPG-sign commits.
+	GPG-sign commits. The `keyid` argument is optional and
+	defaults to the committer identity; if specified, it must be
+	stuck to the option without a space.
 
 --continue::
 -r::

Documentation/git-cherry-pick.txt

@@ -9,7 +9,7 @@ SYNOPSIS
 --------
 [verse]
 'git cherry-pick' [--edit] [-n] [-m parent-number] [-s] [-x] [--ff]
-		  [-S[<key-id>]] <commit>...
+		  [-S[<keyid>]] <commit>...
 'git cherry-pick' --continue
 'git cherry-pick' --quit
 'git cherry-pick' --abort
@@ -101,9 +101,11 @@ effect to your index in a row.
 --signoff::
 	Add Signed-off-by line at the end of the commit message.
 
--S[<key-id>]::
---gpg-sign[=<key-id>]::
-	GPG-sign commits.
+-S[<keyid>]::
+--gpg-sign[=<keyid>]::
+	GPG-sign commits. The `keyid` argument is optional and
+	defaults to the committer identity; if specified, it must be
+	stuck to the option without a space.
 
 --ff::
 	If the current HEAD is the same as the parent of the

Documentation/git-commit-tree.txt

@@ -56,7 +56,9 @@ OPTIONS
 
 -S[<keyid>]::
 --gpg-sign[=<keyid>]::
-	GPG-sign commit.
+	GPG-sign commits. The `keyid` argument is optional and
+	defaults to the committer identity; if specified, it must be
+	stuck to the option without a space.
 
 --no-gpg-sign::
 	Countermand `commit.gpgSign` configuration variable that is

Documentation/git-commit.txt

@@ -13,7 +13,7 @@ SYNOPSIS
 	   [-F <file> | -m <msg>] [--reset-author] [--allow-empty]
 	   [--allow-empty-message] [--no-verify] [-e] [--author=<author>]
 	   [--date=<date>] [--cleanup=<mode>] [--[no-]status]
-	   [-i | -o] [-S[<key-id>]] [--] [<file>...]
+	   [-i | -o] [-S[<keyid>]] [--] [<file>...]
 
 DESCRIPTION
 -----------
@@ -314,7 +314,9 @@ changes to tracked files.
 
 -S[<keyid>]::
 --gpg-sign[=<keyid>]::
-	GPG-sign commit.
+	GPG-sign commits. The `keyid` argument is optional and
+	defaults to the committer identity; if specified, it must be
+	stuck to the option without a space.
 
 --no-gpg-sign::
 	Countermand `commit.gpgSign` configuration variable that is

Documentation/git-grep.txt

@@ -160,12 +160,15 @@ OPTIONS
 	For better compatibility with 'git diff', `--name-only` is a
 	synonym for `--files-with-matches`.
 
--O [<pager>]::
---open-files-in-pager [<pager>]::
+-O[<pager>]::
+--open-files-in-pager[=<pager>]::
 	Open the matching files in the pager (not the output of 'grep').
 	If the pager happens to be "less" or "vi", and the user
 	specified only one pattern, the first file is positioned at
-	the first match automatically.
+	the first match automatically. The `pager` argument is
+	optional; if specified, it must be stuck to the option
+	without a space. If `pager` is unspecified, the default pager
+	will be used (see `core.pager` in linkgit:git-config[1]).
 
 -z::
 --null::

Documentation/git-merge.txt

@@ -10,7 +10,7 @@ SYNOPSIS
 --------
 [verse]
 'git merge' [-n] [--stat] [--no-commit] [--squash] [--[no-]edit]
-	[-s <strategy>] [-X <strategy-option>] [-S[<key-id>]]
+	[-s <strategy>] [-X <strategy-option>] [-S[<keyid>]]
 	[--[no-]rerere-autoupdate] [-m <msg>] [<commit>...]
 'git merge' <msg> HEAD <commit>...
 'git merge' --abort
@@ -67,7 +67,9 @@ include::merge-options.txt[]
 
 -S[<keyid>]::
 --gpg-sign[=<keyid>]::
-	GPG-sign the resulting merge commit.
+	GPG-sign the resulting merge commit. The `keyid` argument is
+	optional and defaults to the committer identity; if specified,
+	it must be stuck to the option without a space.
 
 -m <msg>::
 	Set the commit message to be used for the merge commit (in

Documentation/git-rebase.txt

@@ -294,7 +294,9 @@ which makes little sense.
 
 -S[<keyid>]::
 --gpg-sign[=<keyid>]::
-	GPG-sign commits.
+	GPG-sign commits. The `keyid` argument is optional and
+	defaults to the committer identity; if specified, it must be
+	stuck to the option without a space.
 
 -q::
 --quiet::

Documentation/git-revert.txt

@@ -8,7 +8,7 @@ git-revert - Revert some existing commits
 SYNOPSIS
 --------
 [verse]
-'git revert' [--[no-]edit] [-n] [-m parent-number] [-s] [-S[<key-id>]] <commit>...
+'git revert' [--[no-]edit] [-n] [-m parent-number] [-s] [-S[<keyid>]] <commit>...
 'git revert' --continue
 'git revert' --quit
 'git revert' --abort
@@ -80,9 +80,11 @@ more details.
 This is useful when reverting more than one commits'
 effect to your index in a row.
 
--S[<key-id>]::
---gpg-sign[=<key-id>]::
-	GPG-sign commits.
+-S[<keyid>]::
+--gpg-sign[=<keyid>]::
+	GPG-sign commits. The `keyid` argument is optional and
+	defaults to the committer identity; if specified, it must be
+	stuck to the option without a space.
 
 -s::
 --signoff::

Documentation/git-status.txt

@@ -53,8 +53,9 @@ OPTIONS
 --untracked-files[=<mode>]::
 	Show untracked files.
 +
-The mode parameter is optional (defaults to 'all'), and is used to
-specify the handling of untracked files.
+The mode parameter is used to specify the handling of untracked files.
+It is optional: it defaults to 'all', and if specified, it must be
+stuck to the option (e.g. `-uno`, but not `-u no`).
 +
 The possible options are:
 +

Documentation/git-tag.txt

@@ -9,7 +9,7 @@ git-tag - Create, list, delete or verify a tag object signed with GPG
 SYNOPSIS
 --------
 [verse]
-'git tag' [-a | -s | -u <key-id>] [-f] [-m <msg> | -F <file>]
+'git tag' [-a | -s | -u <keyid>] [-f] [-m <msg> | -F <file>]
 	<tagname> [<commit> | <object>]
 'git tag' -d <tagname>...
 'git tag' [-n[<num>]] -l [--contains <commit>] [--points-at <object>]
@@ -24,19 +24,19 @@ to delete, list or verify tags.
 
 Unless `-f` is given, the named tag must not yet exist.
 
-If one of `-a`, `-s`, or `-u <key-id>` is passed, the command
+If one of `-a`, `-s`, or `-u <keyid>` is passed, the command
 creates a 'tag' object, and requires a tag message.  Unless
 `-m <msg>` or `-F <file>` is given, an editor is started for the user to type
 in the tag message.
 
-If `-m <msg>` or `-F <file>` is given and `-a`, `-s`, and `-u <key-id>`
+If `-m <msg>` or `-F <file>` is given and `-a`, `-s`, and `-u <keyid>`
 are absent, `-a` is implied.
 
 Otherwise just a tag reference for the SHA-1 object name of the commit object is
 created (i.e. a lightweight tag).
 
 A GnuPG signed tag object will be created when `-s` or `-u
-<key-id>` is used.  When `-u <key-id>` is not used, the
+<keyid>` is used.  When `-u <keyid>` is not used, the
 committer identity for the current user is used to find the
 GnuPG key for signing. 	The configuration variable `gpg.program`
 is used to specify custom GnuPG binary.
@@ -63,8 +63,8 @@ OPTIONS
 --sign::
 	Make a GPG-signed tag, using the default e-mail address's key.
 
--u <key-id>::
---local-user=<key-id>::
+-u <keyid>::
+--local-user=<keyid>::
 	Make a GPG-signed tag, using the given key.
 
 -f::
@@ -125,14 +125,14 @@ This option is only applicable when listing tags without annotation lines.
 	Use the given tag message (instead of prompting).
 	If multiple `-m` options are given, their values are
 	concatenated as separate paragraphs.
-	Implies `-a` if none of `-a`, `-s`, or `-u <key-id>`
+	Implies `-a` if none of `-a`, `-s`, or `-u <keyid>`
 	is given.
 
 -F <file>::
 --file=<file>::
 	Take the tag message from the given file.  Use '-' to
 	read the message from the standard input.
-	Implies `-a` if none of `-a`, `-s`, or `-u <key-id>`
+	Implies `-a` if none of `-a`, `-s`, or `-u <keyid>`
 	is given.
 
 --cleanup=<mode>::
@@ -166,7 +166,7 @@ it in the repository configuration as follows:
 
 -------------------------------------
 [user]
-    signingKey = <gpg-key-id>
+    signingKey = <gpg-keyid>
 -------------------------------------