The MLB Amateur Draft is unique in that sometimes, the players ignore that they've been drafted and head off to college for three years. That doesn't mean the NCAA doesn't suspect these kids of breaking the rules.
Below, courtesy Sports Agent Blog, is an email questionnaire—which they received from a Division I recruit—that the NCAA sent to incoming freshmen that were drafted but either did not sign contracts in time to head off to the minors or just decided they would rather attend college. Needless to say, it is hyper-specific and laughable given what we know about the revenue generated by college athletics.
Prospective Baseball Student-Athlete Questionnaire [Sports Agent Blog]