Amid a brewing row over the interpretation of the laws governing tackling, which saw Manchester City defender Vincent Kompany dismissed in the FA Cup clash with Manchester United, but not Liverpool's Glen Johnson for a similar incident against City just days later, O'Neill has called for greater clarity.
He said: "There's a bit of ambiguity about it, really, and I think what they are doing now is going to come down hard on two-footed challenges."
He added: "I think at least if there is some sort of clarity about it, then that can only be good because people are a wee bit confused that some two-footed challenges are going unpunished and other ones are causing a bit of concern.
"I understand the referees having a bit of a problem over it, but in truth, if you are lunging in two-footed and your two feet are off of the ground, there's a fair chance if you come into contact with an opponent's ankle, you are going to cause problems. If that's the case, then so be it - I would agree with that.
"You may always get some sort of an example where you think that shouldn't be the case, but if you are going to run with it, I think the best thing to do is outlaw it and then we will be okay."
It was reported on Friday in the Daily Mail that referees' chief Mike Riley is set to instruct officials to show a straight red card for any two-footed challenge. Professional Game Match Officials Limited were not available for comment.
Norwich manager Paul Lambert believes the reported new ruling is fraught with problems but he understands why referees could be ordered to take such a stance.
"I can understand why. It can be a dangerous tackle. If you are leaving the ground you can hurt somebody," said Lambert. "The British game is totally different from the foreign game. You see some tackles in foreign games and referees just throw a card right away. In Britain it is a bit more hardened than that.
"I still think it will be a hard one to call. Referees have got a really hard job, especially with how quick the game goes."