keeping up-to-date with both branches and tags on the remote is
a common use-case the `--prune-tags` option can be supplied along with
`--prune` to prune local tags that don't exist on the remote, and
force-update those tags that differ. Tag pruning can also be enabled
with `fetch.pruneTags` or `remote.<name>.pruneTags` in the config. See
linkgit:git-config[1].

The `--prune-tags` option is equivalent to having
`refs/tags/*:refs/tags/*` declared in the refspecs of the remote. This
can lead to some seemingly strange interactions:

------------------------------------------------
# These both fetch tags
$ git fetch --no-tags origin 'refs/tags/*:refs/tags/*'
$ git fetch --no-tags --prune-tags origin
------------------------------------------------

The reason it doesn't error out when provided without `--prune` or its
config versions is for flexibility of the configured versions, and to
maintain a 1=1 mapping between what the command line flags do, and
what the configuration versions do.

It's reasonable to e.g. configure `fetch.pruneTags=true` in
`~/.gitconfig` to have tags pruned whenever `git fetch --prune` is
run, without making every invocation of `git fetch` without `--prune`
an error.

Pruning tags with `--prune-tags` also works when fetching a URL
instead of a named remote. These will all prune tags not found on
origin:

------------------------------------------------
$ git fetch origin --prune --prune-tags
$ git fetch origin --prune 'refs/tags/*:refs/tags/*'
$ git fetch <url-of-origin> --prune --prune-tags
$ git fetch <url-of-origin> --prune 'refs/tags/*:refs/tags/*'
------------------------------------------------

OUTPUT
------

The output of "git fetch" depends on the transport method used; this
section describes the output when fetching over the Git protocol
(either locally or via ssh) and Smart HTTP protocol.

The status of the fetch is output in tabular form, with each line
representing the status of a single ref. Each line is of the form:

-------------------------------
 <flag> <summary> <from> -> <to> [<reason>]
-------------------------------

When using `--porcelain`, the output format is intended to be
machine-parseable. In contrast to the human-readable output formats it
thus prints to standard output instead of standard error. Each line is
of the form:

-------------------------------
<flag> <old-object-id> <new-object-id> <local-reference>
-------------------------------

The status of up-to-date refs is shown only if the --verbose option is
used.

In compact output mode, specified with configuration variable
fetch.output, if either entire `<from>` or `<to>` is found in the
other string, it will be substituted with `*` in the other string. For
example, `master -> origin/master` becomes `master -> origin/*`.

flag::
	A single character indicating the status of the ref:
(space);; for a successfully fetched fast-forward;
`+`;; for a successful