Originally Posted by
PilotJames
That's runway code rather than aircraft code
Well yes and no. It describes the aerodrome, but in terms of the aircraft it's intended for. From Annex 14:
"The code is composed of two elements which are related to the aeroplane performance characteristics and dimensions. Element 1 is a number based on the aeroplane reference field length and Element 2 is a letter based on the aeroplane wingspan and the outer main gear wheel span".