It IS a TLA for Professionally Qualified Officer. These creatures can be easily distinguised by their Helicopter-LZ-like berets and complete lack of any military bearing or poise. However, their utter devotion to their chosen careers and their superior intelligence means they are an incredibly valuable asset to the forces (ie. They can probably have a go at your job, you would be breaking the law if you tried to do theirs). Plus, not all the girls have massive arrses, which is something of a bonus.
There is, however, a reason why their commissioning course is known as the Tarts and Vicars course. And I have yet to see the Army Legal Service crewing a Snatch.