Basically, the format for TCG English cards would be XXXX-EN001, or XXXX-ENSP1 for a Sneak Preview card, XXXX-ENSE1 for a Special Edition card
(1/19/2018) In silver-bordered games using Contraptions, you have three sprockets, illustrated on the back of Contraption cards
Common or less valuable cards should be stored in binders - preferably with sleeves on - and valuable cards should be put into toploaders and kept safe
GX Manga Promotional Cards (Yu-Gi-Oh
For Branded players, this is a game-changer that punishes unprepared opponents
I wont go into extensive detail or complete depth of the entire format here, but you can find out everything there is to know by checking out Jason Klaczynskis blog, where he does an excellent job of explaining the format and its history