+-a, \--append::
+ Append ref names and object names of fetched refs to the
+ existing contents of $GIT_DIR/FETCH_HEAD. Without this
+ option old data in $GIT_DIR/FETCH_HEAD will be overwritten.
+
+-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.
+