-a, \--append:: Append ref names and object names of fetched refs to the existing contents of `.git/FETCH_HEAD`. Without this option old data in `.git/FETCH_HEAD` will be overwritten. -f, \--force:: -t, \--tags:: -u, \--update-head-ok:: By default `git-fetch` refuses to update the head which corresponds to the current branch. This flag disables the check. Note that fetching into the current branch will not update the index and working directory, so use it with care.