In Australia it was, maybe still is, AUSTEO. Australian Eyes Only, which was additional to normal classifications. (No, I’m not giving anything away, because it’s been published.) Like most classifications, at times it seemed to be applied randomly.
There’ve been periods where the US has tightened up on what it gave us, because of concerns about leaks at our end. At least one of those periods related to a suspected mole or moles in our intelligence services, and I don’t think the issue was ever satisfactorily resolved.
ASIS http://www.abc.net.au/lateline/stories/s249979.htm
ASIO http://en.wikipedia.org/wiki/Australian_Security_Intelligence_Organisation
I think the UK had similar experiences, for similar reasons.
ASIO, for which I nearly worked a very long time ago in a youthful burst of anti-terrorist sentiment (the 1970’s Red Brigades / Baader Meinhof / Palestinian aeroplane hijacking era), is probably a clown organisation that, because it’s free of pubic scrutiny, can delude itself into believing it actually knows what it’s doing. Until it is subjected to public scrutiny. http://www.smh.com.au/news/national/asio-interrogators-were-grossly-incompetent-judge/2007/11/12/1194766588126.html