As per statement on British Speedway website:-
All NDL regulations are subject to SCB approval.
As part of the British Development regulations, all clubs not competing in the National Development League must participate in at least one of the following alternatives during the season: National League Riders Development Individual, Midland Development League, Northern Junior League, Second Half Open Invitation or a standalone British Youth Championship Round.
Now I wonder when such previous like statements have been made and not adhered to?