Actually, it's "t.u." (lower case letters), also known as "that other university"
One little known fact of Texas Aggie Lore is that the Aggies are responsbible for naming the t.u. mascot, Bevo.
Back in the 20's or 30's, the tradition was that a Texas longhorn steer would be slaughtered for the winner's feast. On one particular game, the Aggies won by 13-0. And some mischievious students snuck into the stable and proceeded to brand the score on the side of the steer.
The t.u. students decided that rather than suffer the permanent embarrasment of having "13-0" branded on the side of their masoct forever, took out their branding irons and changed the 13 into a "B", the hyphen into an "E", added a "V", and left the "0", thus becoming "BEVO"
--TexasMike, Fighting Texas Aggie, Class of '88
PS. No matter what you say, Aggies STILL have one of the more recognizable school rings in the U.S.