AndroidXP called it pretty right. About the only other game I play is the Dawn of War RTS series. Been a fan since I was in school all those years ago, but I haven`t played tabletop for a long, long number of years.
It depends. Mine use to just be "83" as this is the number I've been using since I started sim racing with Papyrus sims. But sometimes when a certain racer joins the server I will change to "th84SUX" or something, hehhehe.
You put your name to number plate so nobody don't need to use those unrealistic signs above cars that seem not to be attached anywhere, yet still they float above car's roof almost magically.
So my plate is my name, simple, effective, it just works.