If I'm on stb tack, and pull the jib clew further to stb in an attempt to push the bows out of irons, that's the same as backwinding?
If you cross-sheet the jib, then yes - I'd have to say you're backing it. If that causes your boat to move astern, then you're subject to rule 21.3 and must stay clear of boats that are not.
Regards,
Eric