| Acronym | Definition |
| D | Dahlonega, Georgia (mint mark, 1838-61) |
| D | Data |
| D | Daytime (broadcasting operating schedule) |
| D | Defense |
| D | Delete(d) (action code) |
| D | Delta |
| D | Depot |
| D | Derated |
| D | Detective (NSW, Australia) |
| D | Detective (police) |
| D | Diameter |
| D | Diesel |
| D | Director (Drone Control; US military aircraft designation; as in D-21) |
| D | District spare (Stores 100 code) |
| D | Doctrine |
| D | Documentary Division |
| D | Drive |
| D | Federal Reserve Bank of Cleveland, Ohio (designates original point of circulation of a dollar bill) |
| d | Surface Drift (US DoD) |
| D | Total Drift, Data (US DoD) |
| D | Undenominated United States Stamp (22 cents, introduced 17 Nov 1985) |