What? On the first move, no square behind a pawn is empty. Or are you saying that pawns should be able to move backwards on any move?
New Rule Suggestion

He actually said the equivocal "first move," rogerwang, though perhaps you're right. Fair enough, but if that's his intention then it might be a long time before any pawn can make a forward move. "Pawn on first move only could be allowed to reverse vertically or diagonally..." To get the center pawns out you would have to spend several moves getting the king and queen out of the way, let the pawns move backwards, then send them out to play.

Dim knight, I think you're misreading the idea. I think he means that on the pawns first move only the player would have the option of moving the pawn to any adjacent empty square.
I don't like this idea either. I think that giving pawns more flexibility makes the game more shallow, rather than adding an extra layer of depth.

Thanks for comments- pawns would only be enabled to move move back from 2nd rank to first rank of course and only to square already vacated by a piece.
Anyway not popular and not going to happen any time soon except perhaps privately in some form or other for fun.

alison27 wrote:
The rules of chess(as per fide) do change from time to time..
Indeed. Changes to the Laws of Chess, Effective 1 July 2005 ...
B 6 This is a re-wording of the old B 5 (b), but then it wanders off, giving the arbiter some more duties (as if he hasn’t got enough to do). I have recently realized that the omission of the old B5(b) restores 7.2, 7.3 and 7.5. This leaves the loophole that a player may request, for instance, the re-location of a displaced piece many moves after the irregularity occurred. This is not in the spirit of Rapidplay and if, for instance, a bishop changed the colour of its squares, this could have been caused by an illegal move (no right to claim this several moves later) or by a displacement of the bishop (definite right to claim). I would suggest that in such cases, we never go back several moves. I haven’t got a clue what advice to give you if you find both kings in check. http://www.bcf.org.uk/organisation/fide/changes-fide-laws_apr05.htm
Still "you" canna change them! Moreover, the rules of piece movement haven't changed in a while.
Pawn on first move only could be allowed to reverse vertically or diagonally into an emptied square; this could improve defence and pawn re-alignment.