In the Air Training Corps this rank is the first NCO rank. However, in the Combined Cadet Force (RAF Section) it is preceeded by Cadet Junior Corporal. In both, however, it is immediately subordinate to the Cadet Sergeant rank.
A cadet is promoted to Corporal by their Commanding Officer (or a representative) if the OC considers them to have good skills and attitude and are capable of handling Parades (Drill); have good knowledge of the ATC at the minimum at Leading cadet classification; and also good leadership, organisation and discipline. Once they meet the requirements, it is up to the OC or other commissioned officer at the Squadron to promote them. The promotion procedure differs from Squadron to Squadron, but is generally to have completed a week long camp of both greens and blues based activities, with an additional week long camp of either of the above, or an adventure training camp. This enables candidates to understand how other Squadrons in their Wing work, and get a wider perspective as to how to lead and organise cadets. Sometimes there is an NCO course run at Wing level which some Squadrons use as a compulsory promotion measure which can enable newer cadets to get ahead of others of same service length as them.
There is usually a minimum service requirement for promotion (which is to have been a cadet for at least 1 year).