gitflow command flags not displayed via help command

hidden_flags.txt

git flow feature finish -DS
  -D = force delete feature branch after finish
  -S = sqash feature during merge

git flow feature pull -r
  -r = pull with rebase

git flow release finish -fns
  -f = use the contents of the given file as a tag message
  -n = don't tag this release
  -S = squash release during merge

git flow hotfix finish -fn
  -f = use the contents of the given file as a tag message
  -n = don't tag this release