Who is number 10

Watched a college football bowl game today. It was the Texas bowl between Baylor and Illinois.  Illinois won big time. I believe it was 38-14.  But that is not what caught my eye about the game.  During the first quarter I noticed that the quarterback's number was 10.  Then on defense another player had number 10.  I have never seen this before.  It must be a new rule where offense and defense players can have the same number. 

In the old days players played on both sides of the ball , offense and defense.  So the rule would not be in then.   I find it weird that two players on the same team have the same number but look at the roster below and see its not just these two players that have that but more.

QUARTERBACK ON OFFENSE

 DEFENSIVE END ON DEFENSE

 BOTH OF THEM TOGETHER

You ever heard of this before.   well till next time