CIA Central Intelligence Agency [US]

CMA Computer Misuse Act (law governing hacking) [UK]

COTS Cheap, Off The Shelf (computer kit; procurement term) [US/UK]

DEA Drug Enforcement Administration [US]

DERA Defence Evaluation and Research Agency (privatized as QinetiQ) [UK]

DGSE Direction Generale de la Securite Exterieure [France]

DIA Defense Intelligence Agency [US]

FBI Federal Bureau of Investigation [US]

FO Foreign Office [UK]

FSB Federal Security Service (formerly known as KGB) [Russia]

GCHQ Government Communications HQ (equivalent to NSA) [UK]

GCSE General Certificate of Secondary Education (high school qualification; not to be confused with GCHQ) [UK]

GRU Russian Military Intelligence [Russia]

JIC Joint Intelligence Committee [UK]

KCMG Knight-Commander of the Most Distinguished Order of St. Michael and St. George (honors service overseas or in connection with foreign or Commonwealth affairs) [UK]

KGB Committee for State Security (renamed FSB in 1991) [Russia]

THE LAUNDRY Formerly SOE Q Department (spun off as a separate organization in 1945) [UK]

MI5 National Security Service (also known as DI5) [UK]

MI6 Secret Intelligence Service (also known as SIS, DI6) [UK]

NEST Nuclear Emergency Support Team [US]

NKVD Historical predecessor organization to KGB (renamed in 1947) [USSR/Russia]

NSA National Security Agency (equivalent to GCHQ) [US]

OBE Order of the British Empire (awarded mainly to civilians and service personnel for public service or other distinctions) [UK]

OCCULUS Occult Control Coordination Unit Liaison, Unconventional Situations [UK/NATO]

ONI Office of Naval Intelligence [US]

OSA Official Secrets Act (law governing official secrets) [UK]

OSS Office of Strategic Services (disbanded in 1945/remodeled as CIA) [US]

Q DIVISION Division within the Laundry associated with R&D [UK]

QINETIQ See DERA [UK]

RIPA Regulation of Investigatory Powers Act (law governing communications interception) [UK]

SAS Special Air Service (British Army special forces) [UK]

SBS Special Boat Service (Royal Marines special forces) [UK]

SIS See MI6 [UK]

SOE Special Operations Executive (equivalent to OSS, officially disbanded in 1945; see also the Laundry) [UK]

TLA Three Letter Acronym [All]