TYS is an acronym for Thank You Sir. Used when wanting to thank someone quickly, but with class.
"You saved me from drinking that diluted cup of tea. TYS"
Stands for "Thinks You Suck", horde raid guild on Spirestone, PVP server. Lead by Lowpass, warlock extraordinaire. Forced to flee from Runetotem PVE due to growing progression threat from <Reforged>. Some controversy surrounds this transfer, however, as Tys' departure dumped a number of poorly skilled player's onto the <Reforged> roster. See Sherard, eg. The efficacy of this wil lbecome apparent in the Ulduar expac.
The <tys> jerks were blocking the mailbox again. Man, I hate Mushupork, what a jerk.