Documentation/fetch-options.txt

   1 -a, \--append::
   2         Append ref names and object names of fetched refs to the
   3         existing contents of `.git/FETCH_HEAD`.  Without this
   4         option old data in `.git/FETCH_HEAD` will be overwritten.
   5
   6 -f, \--force::
   7         When `git-fetch` is used with `<rbranch>:<lbranch>`
   8         refspec, it refuses to update the local branch
   9         `<lbranch>` unless the remote branch `<rbranch>` it
  10         fetches is a descendant of `<lbranch>`.  This option
  11         overrides that check.
  12
  13 -t, \--tags::
  14         By default, the git core utilities will not fetch and store
  15         tags under the same name as the remote repository;  ask it
  16         to do so using `--tags`.  Using this option will bound the
  17         list of objects pulled to the remote tags.  Commits in branches
  18         beyond the tags will be ignored.
  19
  20 -u, \--update-head-ok::
  21         By default `git-fetch` refuses to update the head which
  22         corresponds to the current branch.  This flag disables the
  23         check.  Note that fetching into the current branch will not
  24         update the index and working directory, so use it with care.