M.I.5 is british intellegence, right? Is it Military Intellegence? In which case, what does the 5 stand for?
MI5 is the domestic secret service, MI6 overseas espionage. There used to be a lot of different ones, which either became obsolete or were amalgamated into the two remainind ones. Wikipedia gives a few examples…finding them all via Google is a task that defeated me last time I tried it.
Yes, it stands for millitary intelligence, and 5 was just a bureau number. Apparently all MI bureaus but MI-5 (internal security) and MI-6 (global security aka espionage) have been discontinued.
Alan Stripp’s Codebreaker in the Far East (OUP, 1989, 1995, p148) gives a “rough guide to the wartime War Office departments” as part of a glossary of technical terms. Stapp admits that the list is actually of little relevance to his book, but includes it because “the information appears so rarely”.
Simplified to avoid most of the qualifications about alterations to it during the war, the list is:
MI 1 Admin
MI 2 Middle East, India, USSR, Northern and Eastern Europe, Scandinavia and the USA.
MI 3 Western Europe (initially including Germany)
MI 4 Maps, then operations
MI 5 Operations in Britain, mostly counter-espionage
MI 6 British intelligence-gathering and counter-espionage abroad
MI 7 Press and propaganda
MI 8 Signals intelligence
MI 9 Enemy and Allied POWs; escape and evasion
MI 10 Technical intelligence
MI 11 Military security
MI 12 Post and telegraph security
MI 13 Not used because it might be seen as unlucky
MI 14 Germany (from May 1940)
MI 15 Aerial photo reconnaissance
MI 16 Scientific intellegence
MI 17 Co-ordination of intelligence
MI 18 Unknown
MI 19 From 1941, enemy POWs
MI L Liason with Allied military attaches
MI L® Liason with USSR
MI R Special forces, until formation of SOE
MI X Recruitment
Because the responsibilities shifted as stuff was divided and rearranged, many other authors writing about British intelligence in WWII commonly get confused about the more minor departments, which is always worth bearing in mind when seeing a reference to them.
(MI12 in the list of examples in Wikipedia seems to be a trivial slip-up.)
Answers on this page contradict some of those (including the absence of MI13) - although any differences are probably explained by changes to the structure over time.
MI5/6 are no longer Military intelligence services. Although the military do have some intelligence services of their own, most of these things are handled by MI5/6.
Officially they are know as the Security Services, but the are quite happy to be known as MI5/6 considering the abbreviation that would be used (ie Security Service).
MI5 even has it’s own web site her.
Business.
Nearly,
MI5 became Security Service or SS
MI6 became Special Inteligence Service or SIS
though the MI notations for these two are still comonly used.
As for a cite, I used to work at GCHQ 
A somewhat amusing thing happened a few weeks back…
I was listening to a talk show on NPR. The segment was about the recent London bombings, and the interviewer was about to bring in an intelligence expert on the phone from England. She (the host) kept saying “M-fifteen” for the name of this agency. And she kept calling it that for the first couple minutes of the interview.
The interview-ee was gracious enough not to correct her point-blank. Eventually she caught on, though you could kind of tell she didn’t know what the hell “MI-5” was supposed to be when he was first discussing it. At some point the light bulb lit up (or maybe someone shouted into her earpiece), and she just suddenly started using the proper name, without remarking on the change.
The moral of the story? There are two actually. (1) Know the names of things before you go on the air, and (2) never use sans-serif typefaces to convey anything important.
‘Saturday at M.I.9’ was Airey Neave [codename Saturday] 's book about running an escapers help chain in WW2. Neave had previously escaped himself from Oflag IVc.
Given that we know the others, you have to figure this is the one to really worry about…
Blimey - i’ve never met anyone else who’s actually read that
Rather good book actually.
MI.9 is mentioned in passing in Tom Sharpe’s Ancestral Vices. One of the characters manages a factory where sex toys are made. He’s managed to keep the operation very discreet because the employees sign the Official Secrets act. It turns out MI.9 has a standing order for dildos and other kinky gear as a means to encourage (then) Cold War defectors.
[sub] Hmph, no takers for “business”? That was a damn fine joke[/sub]
I’m disappointed MI-X wasn’t involved in UFOs, alien abductions and preventing world takeover.
It doesn’t say who or what MI-X are recruiting does it?
A more likely explanation is that a less-dumb producer frantically scribbled “IT’S EM-EYE-FIVE!” on a piece of paper and held it up to the window of the broadcast booth.
No, that would be DI 55.
Thought it was A-51.