Certainly used to be MoD Centre who issued such edicts - in the distant past I was that man. But I hasten to add I would never have recommended or issued such a ban, nor did I for the 3 Christmasses for which I was the man ......
In short I agree with Leopold Bloom's post No 2. Got a few 25 Decs in the log books meself. Allus nice to fly if you've got to be at work.....