There seems to be some general misunderstanding of the OSA. There has never been a requirement to “sign” the OSA any more than you are required to “sign” the Road Traffic Act before you drive a car. Both are Acts of Parliament and apply to all UK citizens (actually subjects!) whether you are aware of them or not. If you transgress, you can be done and ignorance of the Act is no defence in law.
I was never asked to “sign” anything despite having TS and Cosmic TS clearance on a number of occasions and being in charge of things that make veeery loud noises. What actually happened was “indoctrination” and “de-indoctrination”, which pointed out the importance of not circulating the info you were about to/had just seen to any Tom, Dick or Harriet.
I am with the majority of guys here who think it unwise for recently current FJ guys (other streams are available) to talk tactics with anyone who doesn’t “need to know”. When I was working with some ex-Soviet state FJ pilots in the Eastern bloc, I was specifically (if rather clandestinely) asked to talk basic tactics with them because they were about to apply for NATO membership. I had a pretty poor reception until I beat the CO in 1v1 - then they started to listen!
Ah, happy days!
Mog