DNI goes back a long way! Further even than Blinker hall who held the post in WW1 in 'Room 30', let alone Admiral Godfrey in WW2 (I think the only officer to reach 3 stars in the conflict without being knighted - got on the wrong side of Churchill I think, possibly for telling him things he didn't want to hear). Some good books about it all now, grub about on Google to see.
As to Seafarer's NS coder rating (pretty much the lowest twig on the Int tree), the point was that with all classified material, by restricting access on a strict need-to-know basis the Services minimise the risk of material being seen by people who may not recognise its significance. Don't take it personally!
Failures of the vetting process are something else again .. have a look at the Guy Liddell diaries on the internet (with the health warning that they have been edited by David Irving).
Re NS coders, have a look at my National Service dit on RRPedia (advt!).
