"Permission To Contact
Generally, if you are enrolled as a full-time student at an NCAA or National Association of Intercollegiate Athletics (NAIA) four-year school and you want to transfer to a different NCAA school to play, your current school’s athletics director must give written permission-to-contact to the new coach or member of the athletics staff before you or your parents can talk with one of them. That is called having a permission-to-contact letter.
You may write to any NCAA school saying that you are interested in transferring, but the new coach must not discuss transfer opportunities with you unless he or she has received written permission-to-contact from your current school."
http://www.ncaa.org/student-athletes/current/permission-contact