| Abbreviation | Definition |
|---|---|
| HDDI | Host Document Data Interchange |
| HDE | Heavy Duty Equipment |
| HDI | Head To Disk Interference |
| HDIP | Hazardous Duty Incentive Pay |
| HDL | Hardware Design Language |
| HDL | Harry Diamond Laboratories |
| HDLC | High-level Data Link Control |
| HDO | Humanitarian Demining Operations |
| HDOP | Harbor Defense Observation Post |
| HDPLX | Half Duplex |
| HDQRS | Headquarters |
| HDR | Humanitarian Daily Ration |
| HDRSAT | High Data-Rate SATellite terminal |
| HDSB | Heavy Dry Support Bridge |
| HDT | Heavy Duty Trailer |
| HDT | High Density Tape |
| HDTC | Humanitarian Demining Training Center |
| HDU | Hard Disk Unit |
| HDX | Half Duplex |
| HDY | Heavy Duty |