directory specific files such as HEAD, index, etc. `-` may also be
specified as `<commit-ish>`; it is synonymous with `@{-1}`.
+
+If <commit-ish> is a branch name (call it `<branch>` and is not found,
+and neither `-b` nor `-B` nor `--detach` are used, but there does
+exist a tracking branch in exactly one remote (call it `<remote>`)
+with a matching name, treat as equivalent to
+------------
+$ git worktree add --track -b <branch> <path> <remote>/<branch>
+------------
++
If `<commit-ish>` is omitted and neither `-b` nor `-B` nor `--detach` used,
then, as a convenience, a new branch based at HEAD is created automatically,
as if `-b $(basename <path>)` was specified.