It was produced by NATS for internal use, someone needs a seriously hefty kick up the jacksy for leaking it out.
Well that's as maybe, how dare people abroad not take note of the UK Wireless and Telegraphy Act 19XX (Yawn)! We do live in the internet age, though, and accessing this stuff from abroad where the UK Wireless and Telegraphy Act 19XX (Yawn) doesn't really have much clout. This is a global village now, and we are all villagers. Unless MI5, MI6, in fact MI7-25 are going to monitor what we download and send suits to beat me up, we might as well learn to accept government imposed censorship is becoming a tad difficile!