The Sanford one was a signatory departure/arrival put into place after the airport went to class C airspace. It was to ease the transition for tower and Orlando Approach with all the VFR dep and arr for the flight schools. It essentially kept clearance del. from having to issue a discreet squack just so you could depart airspace. It did help out in the begining. When it first was derived, you had to have your school sign a letter stating request to use it hence the name (signatory dep./arr. ), but they used to always ask if you were familiar with it, they never forced it on a transitory pilot, to my knowledge like what sounds like they were trying to do in NJ, to that pilot.