MoD Name Allocation System
Wader2 almost hit the nail on the head. The truth of the matter is that each (RAF) Squadron is allocated a series of names. The names such as Ben Dover, Hugh Jardon, Albert O'Balsam,Peter File etc are used to confuse the enemy in the event of loss in hostile territory. The names are allocated to aircraft, much in the same way that trains and civil aircraft are given names. Some aircrew choose to use spurious aircrew name badges as a further subterfuge.
Interestingly, the Army choose to put black masking tape over the eyes of certain soldiers on operations to hide their identity, the RAF tried this but lost 2 Tornados and a Harrier as a result. The RAF then chose to disguise identities by using the spurious name allocation system, which you have quite correctly noticed on certain aircraft. Fast Jets only, but that's another story.....