Yellow Cards in the world cup

[Houghsx]

How many yellow cards does a player need to get before he ends up with a match ban. Also, does anybody have a link to where it's states this officially.

Thanks

[LFC_SL]

Two yellows = one match ban - I was reading a story saying if Crouch got a card vs T+T, Walcott, or Rooney may have to be rushed back! But the salte is wiped clean for 2nd knock out round

Can't find link, sorry