UHND.com - Notre Dame Football, Basketball, & Recruiting

Gray shirting is merely delaying your grant in aid for, usually a semester. The kid can enroll in school but doesn't receive a scholarship right away, and can not play nor practice with the team. In fact, many gray shirts don't even attend the school they committed to. Instead they enroll in junior colleges for that period since they have to pay their own way. The practice is common when schools over sign during a recruiting cycle. The gray shirted player could then be counted in the subsequent year's recruiting class.

There are plenty of stories of kids being told at the last minute of the schools plans. The kid then has little choice but to accept as other schools would have stopped recruiting them. On the other hand, a kid who gray shirts is free to accept a subsequent offer from another school without transfer penalties.