Don't know if this is the most current or accurate interpretation, but take it for what it's worth....
NCAA rules are less permissive than NFL rules and require that the five interior linemen, numbered 50-79, never line up as eligible receivers.[4] If an offensive tackle wishes to line up as a tackle-eligible, he must physically change his jersey number to that of an eligible receiver (this, for example, happened in the 1943 Cotton Bowl Classic, when an offensive lineman for Baylor switched from his usual number of 60 to 80 in order to perform the feat).[5] A defensive lineman can line up as a tight end if his number is not between 50 and 79 (defensive players have no positional numbering restrictions in the NCAA).
A similar play is allowed from a kicking formation, where the requirement that all five linemen wear 50-79 is waived. During a fake field goal or punt, a team may line up with extra tight ends and receivers making it not immediately obvious to the defense which players are eligible and which are not. (However, this exemption can only be taken when it is obvious that a kick may be attempted, for instance on fourth down, in the closing seconds of a half, or similar situations. It cannot be used on every down at the college level.)