lineup card question

[Little Jimmy]

I was wondering if there is an "official" way that an umpire should keep track of his lineup card. I ask this because I recently visited the cactusump web sight that had a powerpoint presentation about lineup cards. Their proceedures were understandable but over the years I've come up with my own way of marking the card which is very clear to me. Is there an official way, taught at ASA or other clinics, to maintain a card or are we free to devise our own so long as we are true to the rules and proceedures of the game?