When a player transfers from one NCAA school to another, potential new schools must get permission to contact from the old school before they can talk to the player. D3 players contemplating transfers to other D3 schools can issue their own release, but nearly everyone else needs permission.
This process prevents poaching, but it also creates a bit of a catch-22. A player who wants to transfer can't call or email other schools to advise them of his interest; and the schools can't request permission to contact unless they know a player wants to transfer. Even players who have been cut or had their scholarships pulled have to respect this process.
A common way around this problem is to have a former travel coach serve as an intermediary to advise potential schools that so-and-so is transferring. Sometimes, if the player has been a solid citizen who just isn't likely to get a chance to contribute on the field, his current college coach will offer outplacement assistance and call other schools on his behalf. (The coach has an incentive: if he can help the player land at another four-year school, the transfer doesn't hurt his program's academic progress rate).
In any case, the player (and his family) need to read the current edition of the NCAA transfer guide, figure out what kind of transfer they are considering, and follow the rules for that kind of transfer.
Best wishes,