| ASA | Annual Security Appraisal |
| CDI | Chief of Defence Intelligence |
| CESG | Communications-Electronics Security Group, GCHQ |
| COTS | Commercial off-the-shelf |
| CNI | Critical National Infrastructure |
| CNIP | Critical National Infrastructure Protection |
| CSI | Ministerial Committee on the Intelligence Services |
| CSR | Comprehensive Spending Review |
| DERA | Defence Evaluation and Research Agency |
| DGIA | Defence Geographic and Imagery Agency |
| DIS | Defence Intelligence Staff |
| DPA | Data Protection Act |
| DTI | Department of Trade and Industry |
| DV | Developed Vetting |
| FCO | Foreign and Commonwealth Office |
| *** | *** |
| FRY | Former Republic of Yugoslavia |
| GCHQ | Government Communications Headquarters |
| ISTAR | Intelligence, Surveillance, Target Acquisition and Reconnaissance |
| IT | Information Technology |
| IW | Information Warfare |
| JARIC | Joint Air Reconnaissance Intelligence Centre |
| JIC | Joint Intelligence Committee |
| JSSU | Joint Services Signal Unit |
| KLA | Kosovo Liberation Army |
| MOD | Ministry of Defence |
| NAO | National Audit Office |
| NAP | (GCHQ) New Accommodation Programme (Project) |
| NATO | North Atlantic Treaty Organisation |
| NCIS | National Criminal Intelligence Service |
| NISCC | National Infrastructure Security Co-ordination Centre |
| *** | *** |
| NTAC | National Technical Assistance Centre |
| *** | *** |
| OSA | Official Secrets Acts |
| PAC | Public Accounts Committee |
| PES | Public Expenditure Survey |
| PFI | Private Finance Initiative |
| PFIAB | President's Foreign Intelligence Advisory Board (USA) |
| PSA | Public Service Agreement |
| PSIS | Permanent Secretaries Committee on the Intelligence Services |
| RIP | Regulation of Investigatory Powers (Act) |
| SIE | Romanian Foreign Intelligence Service |
| SIS | Secret Intelligence Service |
| SIV | Single Intelligence Vote |
| SRI | Romanian Intelligence Service |
| UKIMN | United Kingdom Intelligence Messaging Network |
| UKUSA | United Kingdom/USA (Intelligence Agreement) |
| UNIRAS | Unified Incident Reporting and Alert Scheme |
| UOP | Office of State Protection (Poland) |
| VAT | Value Added Tax |
| WSI | Military Intelligence Organisation (Poland) |
| Y2K | Year 2000 problem/Millennium Bug |
