With ITRegistrar you can allow your clubs to enter new players and to assign player ID to the new players, but still require the clubs send in a proof of age (birth certificate). Only the District is able to select the Age Authorize button.
The steps for using the Age Authorization feature are:
Club enters new player
Club is able to edit the birthday.
Club submits proof of age to the District
District checks documentation and selects the Authorize button.
The birthday is then frozen (the club cannot edit the birthday, if they have any changes they have to contact the district).
Since the birthday is locked any future club registering that player does not require a proof of age since it has already been supplied and approved by the district.