Red Card = banned immediately, usually for 1 game although it can be 2 games (using offensive or insulting or abusive language/gestures) or 3 games (Violent Conduct, Serious Foul Play or spitting at an opponent or any other person). All these bans are increased by 1 further game if it is a second red within one season, or by two extra games if it is a third red etc.
5 yellows = banned for 1 game, ban starts 7 days after getting 5th card. Free to play until then. This ban for accumulation of yellows only applies for cards picked up by end of Feb.
10 yellows = banned for 2 games, ban starts 7 days after getting 10th card. Free to play until then. This ban for accumulation of yellows only applies for cards picked up by second sunday in April
15 yellows = banned for 3 games, ban starts 7 days after getting 15th card. Free to play until then. This ban for accumulation of yellows applies all season.
Sent off for 2 yellows = a red card and you are banned accordingly. These yellows do NOT count for accumulation of yellows purposes.
Eligible Matches = Premiership, FA Cup, Carling Cup (basically all first team competitive, non-European games). This applies to both when they get the cards and when they are banned.