Documentation/filters.txt

   1 When combining multiple `--contains` and `--no-contains` filters, only
   2 references that contain at least one of the `--contains` commits and
   3 contain none of the `--no-contains` commits are shown.
   4
   5 When combining multiple `--merged` and `--no-merged` filters, only
   6 references that are reachable from at least one of the `--merged`
   7 commits and from none of the `--no-merged` commits are shown.