Tuc, you remind me, there is a QR(RAF) about 1260 IIRC that refers to the authorised engineer or some such.
As my unit was contractorised and essentially Army centric, having been an RAF unit, the need for an authorised engineer was novel. Our contract manager spotted the anomaly and volunteered to undertake the role, he was an ex-RAF SEngO. Oh, and at no cost.