| Subject | English | Thesaurus |
| avia., Canada | CMNPS transition area | The area within the Canadian Domestic Airspace (CDA) extending upwards from FL 280, underlying the designated CMNPS airspace |
| abbr., IT | Custom Local Area Signaling Services | CLASS |
| IT, abbr. | Custom Local-Area Signaling Services | CLASS |
| telecom., abbr. | Custom Local Area Signaling Services | CLASS (Bellcore) |
| law, abbr. | High Intensity Drug Trafficking Area | HIDTA |
| abbr., avia. | High Intensity Radio Transmission Area | HIRTA (Interex) |
| telecom., abbr. | Local Area Signaling Services | LASS |
| relig., abbr. | Lutheran Social Services of the National Capital Area | LSS-NCA |
| abbr., scottish | Military Area Services | MAS |
| avia., Canada | transition area | An area established when it is deemed advantageous or necessary to provide additional controlled airspace for the containment of IFR operations |
| abbr. | U.S. area phone code Canada/Services | 600 |
| abbr. | U.S. area phone code Directory Services | 411 |
| abbr. | U.S. area phone code Emergency Services | 911 |
| abbr. | U.S. area phone code Government Emergency Telecom Service | 710 |
| abbr. | U.S. area phone code Repair Service | 611 |
| abbr. | U.S. area phone code Service access code | 200 |
| comp., net., abbr. | Wide Area File Services | WAFS |
