In other words, if a coach offers an OV will the athlete need to sign some sort of contract to lock in the visit?
At a D1 or D2 school, you have to register with the NCAA clearinghouse.
As I recall, there was the emailing of the itinerary and plane ticket, but there was no document to sign indicating that this constitutes an official visit.
Agree with above. Just provide the Clearinghouse identifier to the coach.
The only thing close to official was a confirmation email from the athletic person that arranged travel to confirm legal name and dates for plane tickets and transportation.