Because junior players require cards I think you'll find it's a bit different than open age Neil. Open age players only sign for one season, and whilst juniors re-register every year, if they don't re-register for their club the following year they still have to transfer. A player can only have a card for one club, and rugby league services issue the cards for both RFL and BARLA teams. Players would have to de-register from their BARLA club to register for an RFL club and visa versa at the end of your season to avoid conflicts and the database exploding!