Actually, if it were a card game, playable users would need their ID listed on the card.
There's a few kinds of playable cards - Users and Add-Ons particularly. Add-Ons are associated with events which display effects on the playing field. Played Add-Ons must be attached to a user in play before being used.
Users have several classes - Host, SA, Admin, Normal, and Noob. SA and Host are among the top tier class of playable user cards. Only 1 Host is permitted per deck.
The classes of user cards change the color of the card itself.
Host - Orange
SA - Yellow
Admin - Silver/Grey
Normal - Blue
Noob - Black
All Add-On cards are green.
Well, that was fun.