mi1: code-breaking (see gchq)
mi2: russia and scandinavia
mi3: eastern europe
mi4: aerial reconnaissance
mi5: domestic intelligence (now security service)
mi6: foreign intelligence (now secret intelligence service)
mi7: propaganda
mi8: military communication interception (see gchq)
mi9: undercover operations, pow escape
mi10: weapons analysis
mi11: field security police
mi12: military censorship
mi13: reconnaissance
mi14 and
mi15: german specialists
mi16: scientific intelligence
mi17: military intelligence "head office"
mi18: unknown (may have never existed) (reason to believe north america)[citation needed]
mi19: pow debriefing
