Nth n: Launch n times the corresponding command, and delete it. A way to implement it may be to decrement gradualy by rewriting RC file, each time the command is launched successfully (exit status = 0).
Once: Alias for Nth 1
Depend id: Launch the id task before corresponding command
Loop: Run in loop, aliasing Depend selfwhere self is the id of the command to which Loop is attached.
Disable: Do not launch corresponding entry
Commentcmt: Attach comment "cmt" to the given entry. May be displayed.
Log: Signal we would like to log outpout of the corresponding command. Related to #18.