Although the N and S series had earlier been used by RNAS aircraft, the sequence N1000 to N9999 was again used by the Air Ministry for both RAF and RN aircraft.
儘管N和S系列已經早被RNAS飛機使用了，N1000到N9999還是被空軍部混用於皇家空軍和皇家海軍的飛機上。