Most players at this level would be 'non contract' players. Basically it means, there is no obligation on the club to pay them if for example they get injured or dont get picked to play
They would have simply signed unibond registration forms to play for the club. It also means if at any time of the season another club wishes to sign them they can, without any transfer fee or delays.
The only exception to that rule, if my memory serves is that any fellow Unibond teams that may wish to sign him have to at first put in a 'seven day approach' to the club before they can speak to him
Other anomolies include the fact that if they so wish, any player on non contract forms can sign for any other non unibond team and in reality be dual registered
Players on contracts, the terms of which are then officially recorded with the FA means, their wages are paid regardless of whether they actually play and if they get injured, even if they are out for the season, they still have to be paid
It also means if another club wishes to have them playing for them, a transfer fee normally has to be agreed
You will find, the best players, and certainly the younger ones with bight prospects would, if budgets allow it, nearly always be on contracts