Abort: The termination of a mission or project.
Access: Means to identify or obtain use of the desired target for operational purposes.
Accommodation Address: A "safe" address without obvious connection to an intelligence agency, used for a person that does not occupy the premises. This address might be a prearranged temporary address or location where an intelligence operative may receive, forward, transmit, or relay mail to another intelligence operative or outside party. 
Action Officer: A case officer supporting intelligence activities designated to use direct or indirect means to affect enemy operations.
Agent: A person authorized and trained to obtain or assist in securing information for intelligence purposes. It may also represent a person who engages in clandestine activities under the direction of an intelligence organization, but is not an officer, employee, or co-opted worker of that organization.
Agent-in-Place: A penetration agent that betrays its organization to an enemy service by providing information from their actual location that is usually behind enemy lines.
Agent of Influence: Someone who privately serves the interests of a foreign power that can be identifiable by subversive political associations or activities.
Agent Net: An intelligence-gathering unit of agents supervised by a principal agent who is reports to an intelligence officer.
Agent Provocateur: A person used by intelligence agencies to provoke the desired reaction from a target.
Alias: A false name used by intelligence operatives and criminals to insulate themselves from identification. Covert operations and illegal undertakings often require deception to assure concealment.    
Analysis: The process by which information is transformed into intelligence; a systemic examination of information to identify significant facts, make judgments, and draw conclusions.
Assassination: One Central Intelligence Agency (CIA) employee called it "termination with extreme prejudice". The KGB (Soviet Intelligence Agency) described it as "Wet Work". Assassination is another historically observable method of removing political enemies used by intelligence and criminal organizations.
Alias: False names often used by criminals and intelligence operatives to conceal their identity. 
Asset: Human or technical resources used by an intelligence or security service for operational purposes.

Backstop: Attempts to legitimize the undercover status adopted by intelligence agents. These agents require backstopping to prevent hostile discovery of their actual background. Methods range from rudimentary (false biographical information) to complex (networks of front corporations with employees).
Barium Meal: The use of traceable information for Counterintelligence purposes to reveal enemy networks or operatives.
Black Bag: A term used to describe illegal or clandestine operations involving entry into a desired but prohibited location.
Black Boxed: A portion of operational activities that cannot be assessed following intelligence action due to circumstances beyond direct control.
Black List: The list includes the location and identity of individuals whose capture and detention are of prime importance.
Black Operations (Black Ops): Operations that cannot be acknowledged and must be covertly undertaken. Such operations are illegal and often involve actions that would be catastrophic to the perpetrator and their organization if discovered.
Black Radio: Radio stations with concealed origins that use programming to influence listeners and misinform them for the dissemination of propaganda. 
Blowback: This informal word refers to unintended consequences resulting from operational decisions.
Bona Fides: Establishing the credibility of an individual based upon credentials.
Brush Contact: A method of quick interaction to minimize agent exposure during meetings. Often resources, instructions, or items can be exchanged without being monitored.
Bubble: Areas equipped with soundproofing to prevent any hostile or external monitoring of internal conversations.
Bug: A concealed electronic surveillance device of reduced size used to gather intelligence.
Burned: When an intelligence operative or employee is compromised.
Burning Bridges: Disrupting a compromised intelligence network to sever operational ties and prevent future communication between agents. Burn Notice: A warning distributed to intelligence employees and operatives to end contact with an individual determined unreliable.
Burst Transmission: Signals that are compressed and transmitted in quick bursts to avoid interception.

Case Officer: The professional employee of an intelligence or counterintelligence organization that is responsible for providing direction for an agent operation.
Clandestine: Concealment used to protect secret undertakings.
Clandestine Imaging Division: The CIA's Technical Services Clandestine Imaging Division that offered technical support for operations using varied technological intelligence gathering methods. 
Clandestine Services: An internal CIA term, it references the former Directorate for Plans and current Directorate of Operations.
Classification: Security levels assigned to information to prevent unauthorized disclosure.
Clearance: The authorization level of information a person is allowed to access in a national organization.
Collection: Acquiring desired information that can be processed by analysts for intelligence data.
Compartmentalization: The creation of separate units within an organization that possess varying levels of access to sensitive information. This method allows increased control and security to prevent the disclosure of secrets.
Confidential: Security classification applied to information, the unauthorized disclosure of which reasonably could be expected to cause damage to the national security that the original classification authority is able to identify or describe.
Confusion Agent: An individual dispatched by his sponsors to confound the intelligence or counterintelligence apparatus of another country rather than to collect and transmit information.
Contact Report: A report of an operational event. This format provides officers the ability to document routine aspects of operational activities not otherwise covered by other intelligence or operational reporting.
Control: The capacity of a case officer (and his service) to generate, alter, or halt agent behaviors by using or indicating his capacity to use physical or psychological means of leverage.
Counterintelligence: Deceptive methods used to assess and penetrate enemy intelligence groups.  These include the use of surveillance, infiltration with double agents, inspiring defectors, and compromising adversarial operations.
Cover: False background or credentials adopted to conceal intelligence agents engaged in clandestine operations. The only type of cover protected by the Vienna Convention from arrest or prosecution is diplomatic cover.
Covert Action: An officially unrecognized operation inspired to promote foreign policy objectives. US Government covert action has employed paramilitary groups, the Mafia, and the recruitment of assassins.
Cryptology: The academic study, development, and deciphering of codes. 
Cryptonym: A false name used to conceal various people, places, and things related to intelligence operations. The CIA for instance combines a locational prefix and a secondary word to represent concealed information. Certain cryptonyms can relate to a group project and specific members of the operation.
Cultivation: The time preceding agent recruitment during which an intelligence officer utilizes a handler to determine if recruitment is desirable. Often this contact is during a social event to conceal its true purpose.
Cutout: An intermediary or device used to remove direct contact between members of a clandestine organization by compartmentalizing their communications to allow greater security.

Damage: Harmful adversarial countermeasures that reduce viable intelligence operations from being undertaken.
Damage Assessment: An internal review conducted to determine how to best minimize damage from legal proceedings resulting from intelligence operations.
Dangle: Intelligence agents used with the intention of manipulating enemy agents to attempt recruitment. This provides opportunity for the "dangle" to penetrate the enemy group.
Debriefing: An interview conducted with a voluntary source to assess topics and areas of intelligence or national security interest by the systematic review of observational data.
Dead Drop: Using a remote or lightly traveled area to exchange information and messages. These drops often employ concealed messages hidden in the surrounding environment for retrieval.
Deep Cover: A cover status designed to withstand scrutiny by opposing groups through diligent fabrication of all related credentials. Defection: Conscious abandonment of loyalty, duty, and principle to one's country.
Defector: A defector is a person who betrays their side in a conflict for opposing forces to the detriment of their original side. Often they are a citizen whose public disloyalty potentially is utilized to advance hostile external intelligence goals.
Defector in Place: Defectors located within their country of origin serving a hostile power.
Denied Areas: Hostile areas that usually prevent intelligence operations from being undertaken covertly.  Enhanced counterintelligence methods and precautions should be used within such areas to remain undetected by enemy groups.
Diagraph: A CIA designated two-letter locational prefix referencing the Agency division responsible for managing varying related matters that included code-named agents, sources, projects, and operations.
Diplomatic Bags and Couriers: These bags are utilized for delivery of sensitive information. Couriers enjoy diplomatic immunity from search and seizure. Bags and couriers are protected under the Vienna Convention. 
Diplomatic Immunity: A status wherein diplomatic officers accredited to a foreign government as ambassadors, or other public ministers, are immune from the jurisdiction of all courts and tribunals of the receiving states whether criminal or civil. The status of diplomatic immunity protects the bearer from prosecution, civil suit, punishment, or compelled testimony in the country to which he or she is accredited.
Discard: The intentional sacrificing a lesser spy to distract notice from a vital agent.
Disinformation: Using a wide array of false information to discredit chosen targets privately or publicly or mislead enemy agents and the public.
Double Agents: Agents in contact with two opposing intelligence services, this agent simultaneously betrays one agency while serving the other. 

Electronic Intelligence: Using electronic media to collect and analyze signals intelligence.
Émigré: A person lawfully emigrates from their country with the intention of resettling abroad.
Evidence: Legal items and sources presented that prove or refute allegations.
Exfiltration: The covert process of removing someone from a target area that may require exceptional support and avoidance of border controls.
Expulsion: This is the proscribed diplomatic sanction for a host country under the tenets of the Vienna Convention. A suspected abuser of diplomatic privilege can be named "persona non grata" and thus be required to leave the offended nation within a required amount of time. Eyewash: False entries made in files, usually to protect the security of a source.

False Defector: A seeming foreign defector that maintains loyalty to their original intelligence service, the rarity of these particular agents is notable and far more alleged false defectors have been named rather than proven.
False Flag: Deceptive tactics employed to aid intelligence officials in their own clandestine operations. These tactics are used rarely to assure their impact and prevent full disclosure of important events.
False Flag Defector: A defector that has been recruited but deceived about who they actually serve by an intelligence group. For instance, a person might believe they serve the CIA but could be a pawn of KGB agents that represented themselves as CIA officials. 
Fellow Traveler: Communist allied persons who support their agendas without formal membership.
Front: Using an organization or body to provide cover for intelligence operatives, this association might also provide reasonable excuses for associating with intelligence targets or sources.

Handler: These intelligence employees directly manage an agent or agent network.
Honey Trap: A planned sexual encounter used to compromise a target for blackmail. If the encounter is recorded or witnesses it may be used to threaten exposure creating dire personal or professional consequences. Vulnerable agents and officials have been compromised repeatedly throughout history to serve hostile powers.
Human Intelligence: A significant portion of the most useful intelligence is received and distributed using live intelligence sources. However, these sources are the most difficult to manage and develop. Unlike technical intelligence sources, these sources can betray, fabricate information, and serve hostile groups while seemingly being managed.

Imagery: Photographic Intelligence gathered by technological means that often relies on satellite and high altitude photography. Indoctrination: Instructions and policy information disseminated to intelligence employees conducting assigned programs.
Informant: A person that wittingly or unwittingly provides information to a clandestine service.
In Obscura: Rare instances when intelligence operatives are temporarily obscured from hostile observation.
Intelligence Analysis: It is the ability to render several often-unconnected facets of an issue and assemble these pieces into a single cohesive idea for policy and operational usage. One of the bedrock activities of intelligence is the conversion of raw gathered facts, rumors, and public information into actionable intelligence data.

Measurement and Signals Intelligence: The useful data processed from the analysis of targets and monitoring areas of specific interest with technological means.
Microdot: Concealing important information by drastically reducing its size, this necessitates a microscope to deciphering its contents. The dot can be hidden within other materials to conceal its existence. This method is a low-cost alternative to more complex arrangements.  Misdirection: A classic conjurer's trick, misdirection is the term applied in the counterintelligence community for the tactic of supplying an ostensibly plausible explanation for an event actually caused by something quite different, probably by an individual or an operation, deemed sufficiently valuable to require protection. Invariably a human asset many produce some information which requires action that could compromise him or her, so misdirection is intended to divert attention elsewhere. 
Missile Gap: An exaggerated US military estimate of Soviet nuclear missile capabilities, it occurred in the early 1960s.
Mole: Intelligence agents infiltrating one group while maintaining allegiance to another group who prior enlisted them. The mole potentially can extract secret information, spread dissension among the targeted group, falsely accuse loyal agents, and create chaos in operations they have influence over. The primary use of a mole is penetrating and seriously damaging the target group's operations.
Mole Hunt: A counterintelligence investigation that targets suspected penetration agents within an intelligence group.
Moscow Station: The CIA base inside the Soviet capital city of  Moscow used for Cold War operations after 1953. The first Agency officer sent to Moscow was compromised by hostile blackmail operations. The American Embassy in Moscow was repeatedly the subject of hostile intelligence since that time.
Moscow Rules: The vigorous use of intelligence methods required in only the most hostile of operational environments defined by Moscow, Russia.

Name Trace: A search of available recorded data to find information about a person, normally conducted to determine the presence or absence of derogatory information about them.
Non-Official Cover: A false background used by intelligence agents to undertake operations; however unlike regular cover these agents do not enjoy diplomatic protections and thus require more complex operational protections for success.
Numbers Stations: A shortwave radio station transmission of a seemingly undecipherable numeric code read over the radio. Multiple counties have used this method to distribute hidden instructions and statements to their own assets within foreign areas.   

Open Sources: Public or declassified information that is the source of most intelligence material.
Operational Act: Any undertaking that reveal an individual's intelligence agent status and compromises their operation.
Overt: Activities that are openly acknowledged by or readily attributable to the United States government and include activities designed to acquire information through legal and transparent means. Overt information may be collected by observation, elicitation, or from expert sources.

Penetration: Targeting the existing infrastructure of an enemy intelligence group to access secret material and influence enemy activities.
Persona Non Grata: A Vienna Convention disciplinary measure afforded to countries hosting foreign diplomats. It allows a government to expel designated persons from a country by public or private official declaration. The term means a "person who is not acceptable or welcome."
Pitch: This occurs when an intelligence operative attempts to enlist another person in a secret operation. This act may include no preparation or complex advanced preparation depending on operational priorities.
Plausible Deniability: The need to establish a reasonable cover story to prevent blame from being easily applied to clandestine operations and provides officials the ability to deny secret operations that would incite negative public relations.
Positive Vetting: An internal security measure used to accumulate information on candidates in order to prevent compromised individuals from accessing protected information. This might include a series of interviews, extensive verifiable references, and all required document evidence. Proprietary: Unlike cover organizations, a proprietary is a business owned by the CIA. This does not infer that employees know of the operational use of their company because of a complex web of allied or subsidiary corporate organizations usually supporting these businesses.
Provocation: Activity designed to induce an individual, intelligence service, or government to take action damaging to its own interests. Pseudonyms: A long-term false name used by intelligence operatives and leaders to conceal their identity.

Rabbit: The person targeted by a surveillance operation.
Redaction: For purposes of declassification, the removal of exempted information from copies of a document.
Redefector: An individual who defects from their country of origin and for various decides to return.
Romeo Spies: Male intelligence operatives who are used to stage honey trap plots to compromise enemy female intelligence agents.

Sanitize: The revision of a document to prevent the identification of sources. This usually involves the deletion or substitution of names and other key details.
Secret: The security classification applied to information that unauthorized disclosure could be expected to cause serious damage to national security.
Sheep Dip:  Military operatives removed from normal duties for use in clandestine purposes.
Sleeper: Agents that are placed in a foreign country long in advance of future operations to be later activated without prior alerting enemy intelligence.
Spy Swap: When captured intelligence agents are exchanged by enemy powers.
Spotter: A person assigned to locate and assess individuals in positions of value to an intelligence service.
Station: The term used to signify the CIA base of operations in a given zone or country.
Stay Behind: Intelligence operatives that are purposefully left behind to create disorder and chaos if enemy agents assume control of a territory. Military operations also successfully used this tactic.

Tagging: Methods of physical surveillance to monitor the actions of operational targets. 
Triple Agents: Agents intentionally posing as disaffected operatives to illicit enemy recruitment of them as double agents.

Unwitting: An individual used by an official group that is not aware of their connection to a government agency.

Validation: The process used to determine a source, asset, agent, or employees authenticity, reliability, utility, suitability, and degree of control the case officer or others have.
Volunteer: A person who initiates contact with a government, and who volunteers operation intelligence or requests political asylum; includes call ins, walk ins, and write ins. 

White List: A list of persons and locations approved to provide intelligence support or useful information to allied intelligence operatives. Wilderness of Mirrors: The deceptive landscape that clandestine intelligence gathering and assessment occurs in. This culture deception is false, lies are truth, the reflections are illuminating and confusing. The phrase centers on the problem of reliability of the secret information about espionage and the identity of spies. The mirrors comprise information from defectors, disinformation from opposing sides in the Cold War, deviously covered false trails, and facts thought to be valid but incomplete and later established as totally untrue.   
Witting: An individual used by an official group that is aware of their connection to a government agency.  

Zoning: A method of surveillance in which the surveillance area is divided into zones, and different people are assigned to cover a specific area. 

AA: American Airlines, anti-aircraft
A/C: aircraft
ACIC: Army Counter Intelligence Center
ADSO: Assistant Director of Special Operations

BOB: Bureau of Budget

C/WH: Chief, Western Hemisphere Division
CA: Covert Action
CCS: Central Cover Staff
CE: Counterespionage
CI: Counterintelligence
CIA: Central Intelligence Agency
CIARDS: CIA Retirement and Disability System
CIC: Counter Intelligence Corps
CID: Clandestine Imaging Division
CIG: Central Intelligence Group
CISIG: Counter Intelligence Special Investigations Group
CMA: Mexican Aviation Company
CNE: National Confederation of Students
CNO: Chief of Naval Operations
COG: Continuity of Government
COMINT: Communication Intelligence
COS: Chief of Station
COVCOM: Covert Communications
CP: Communist Party
CR: Contact Report
CS: Clandestine Service
CSA: Covert Security Approval

DCI: Director of Central Intelligence
DDA: Deputy Director for Administration
DDCI: Deputy Director of Central Intelligence
DDO: Deputy Director of Operations
DCOS: Deputy Chief of Station
DDP: Deputy Director for Plans
DDR: Deputy Director of Research
DDS: Deputy Director of Support
DDS&T: Deputy Director Science and Technology
DFS: Department of Federal Security
DI: Directorate of Intelligence
DIA: Defense Intelligence Agency
DO: Directorate of Operations
DOD: Department of Defense
DOE: Department of Energy
DFS: Department of Federal Security
DOD: Department of Defense
DP: Directorate of Plans
DRE: Directorio Revolucianario Estudiantil, Student Revolutionary Directorate
DS: Directorate of Support
D&TO: Developmental and Target of Opportunity

EDT: Estimated time of departure

FIS: Foreign Intelligence Service
FBI: Federal Bureau of Investigation
FI: Foreign Intelligence
FI/INT/RE: Foreign Intelligence Staff, Intelligence Group, Requirements & Evaluation Branch
FRD: Frente Revolucionario Democratico, Revolutionary Democratic Front
HUMINT: Human Source Intelligence
IDN: Identification Number
IG: Inspector General
IISE: Institute of Social and Economic
IO: International Organizations Division
IPN: National Polytechnic Institute
I&NS: Immigration and Naturalization Service
I&R: Inspection and Review Staff

JCS: Joint Chiefs of Staff

MLN: National Liberation Movement
MSS: Mexican Social Secretariat
MSWT: Medium Speed Wireless Transmission
MURO: University Reform Orientation Movement

NCNA: New China News Agency
NIACT: Night Action
NSA: National Security Agency
NSCID: National Security Council Intelligence Directive

OAS: Organization of American States
OO: Office of Operations
OOA: Other Operational Activities
OPC: Office of Policy Coordination
OPF: Official Personnel File
OSO: Office of Special Operations
OSS: Office of Strategic Services
OTR: Office of Training Regulation
OWVL: One-Way Voice Link

PA: Principal Asset
P/A: Political asset
PAN: Party of National Action 
PARM: Authentic Party of the Mexican Revolution
PCM: Communist Party of Mexico
PM: Paramilitary
POA: Provisional Operational Approval
POCM: Workers and Farmers Party of Mexico
PP: Political and Psychological Warfare
PPS: Popular Socialist Party
PRI: Institutional Revolutionary Party

RID: Records Integration Division
RMD: Related Missions Directive

SAB: Sabotage
SAS: Special Affairs Staff
SIGINT: Signals Intelligence
SOI: Special Operational Instruction
SR: Soviet Russian
SRD: Soviet Russian Division
SRS: Security Research Staff
SW: Secret Writing

TDY: Temporary Duty
TELEX: Automatic Teletypewriter Exchange
T/O: Table of Organization
TSD: Technical Services Division
TUI: Trade Union International

UCI: International Civic Union
UN: United Nations
UNAM: National Autonomous University of Mexico
UOM: Mexican Workers University
USAID: United States Agency for International Development
USIA: US Information Agency
USIS: US Information Service
UNSUB: Unknown Subject

WFTU: World Federation of Trade Unions
WH: Western Hemisphere Division