| High Mass Star | Academic & Science |
| Hybrid Male Sterility | Academic & Science |
| Howard Medical Science | Academic & Science |
| Hydrologic Modeling System | Academic & Science |
| Hazard Mitigation Survey | Academic & Science |
| Hellenic Mathematical Society | Academic & Science |
| Ελληνική Μαθηματική Εταιρεία | Academic & Science |
| Ellenike Mathematike Etaireia | Academic & Science |
| Homeshore (ak) | Airport Code |
| Hydraulic Module Speed | Business |
| Hitachi Micro Systems | Business |
| Hughes Missile Systems | Business |
| Home Marketing Services | Business |
| Heavy Metal System | Business |
| Heavy Metal Scrap | Business |
| Hennessey Motor Sports | Business |
| Health Management Systems | Business |
| Highpower Management System | Business |
| Hospitality Management Solution | Business |
| Homeowner Management Services | Business Management |
| Hedge Management System | Business Management |
| Huntingdon Middle School | Community |
| Henry Middle School | Community |
| Hendersonville Middle School | Community |
| Hartsville Middle School | Community |
| Hastings Middle School | Community |
| Hawkins Middle School | Community |
| Headland Middle School | Community |
| Hedrick Middle School | Community |
| Hudson Middle School | Community |
| Harrison Middle School | Community |
| Hindu Marriage System | Community |
| Highland Middle School | Community |
| T. L. Handy Middle School | Community |
| Hutto Middle School | Community |
| Herndon Middle School | Community |
| Housing Management System | Community |
| Hanover Middle School | Community |
| William Hubbard Middle School | Community |
| Harmony Middle School | Community |
| Harris Middle School | Community |
| Hally Middle School, Detroit, Michigan | Community |
| Hawk Mountain Sanctuary | Community |
| Hamburg Middle School | Community |
| Heritage Middle School | Community |
| Harvest Middle School | Community |
| Hays Middle School | Community |
| Home Missionary Service | Community |
| Hammarskjold Middle School | Community |
| He's My Savior | Community |
| Hillcrest Middle School | Community |
| Hartley Melvin Sanborn | Community |
| Home Multimedia Software | Community |
| Harding Middle School | Community |
| Hamden Middle School | Community |
| Hampton Middle School | Community |
| Hillsborough Middle School | Community |
| Homewood Middle School | Community |
| Hurricane Middle School | Community |
| Hampshire Middle School | Community |
| Hinsdale Middle School | Community |
| Hillside Middle School | Community |
| Hahira Middle School | Community |
| Huntington Middle School | Community |
| Hardin Middle School | Community |
| Hamlin Middle School | Community |
| Haverford Middle School | Community |
| Hardware Memory Scrubber | Computer Hardware |
| Hardware Maintenance Reference Manual | Computing |
| Hardware Maintenance and Service | Computing |
| Headend Management System | Computing |
| Home Media Server | Computing |
| Hardware Meets Software | Computing |
| Huawei Mobile Services | Computing |
| Mens' Organic Hemp Slacks (Hemp Mens' Slacks) | General |
| Hamann Motorsport | General |
| Homestead Miami Speedway | General |
| Hickory Motor Speedway | General |
| Helsinki Motor Show | General |
| Hannover Motor Show | General |
| Historic Motor Sports | General |
| Hino Motors Sales | General |
| Hyundai Motor Securities | General |
| Hyundai Motor Singapore | General |
| Hyundai Motorstudio | General |
| Heavy Melting Steel | General |
| Hunting Melin Sons | General |
| Heroically Manned Starship | General |
| Her/His Majesty's Ship | General |
| His/Her Majesty's Ship | General |
| Heavy melting scrap | General |
| Her Majesty s | General |
| Hazard Mapping System | General |
| His Majesty s | General |
| Harold Marshall Sylvester | General |
| Hollowcore Manufacturing System | General |
| Hodg Man S | General |
| Hydrologic Micro Services | General |
| Hotel Management System | General |
| Headland Management System | Governmental |
| Hazardous Materials Safety | Governmental |
| Akhil Bharatiya Hindu Mahasabha | Governmental |
| His Majesty's Ship | Governmental |
| Her Majesty's Ship | Governmental |
| His Majesty's Service | Governmental |
| Here's My Ship | Governmental |
| Highly Migratory Species | Governmental |
| Her Majesty's Service | Governmental |
| Homicide at Mitre Square | Governmental |
| Happy Mask Salesman | Internet |
| Hours Minutes Seconds | Measurement Unit |
| HyperMutation Somatic | Medical |
| Home Medical Service | Medical |
| High-Magnitude Stressor | Medical |
| Hidalgo Medical Services | Medical |
| Harvard Medical School's | Medical |
| Healthcare Management Systems | Medical |
| Healthcare Management System | Medical |
| Health Management System | Medical |
| HyperMobility Syndrome | Medical |
| Heroes of Medicine and Science | Medical |
| Hypertension Management Software | Medical |
| Harvard Medical School | Medical |
| Hospital Management System | Medical |
| Heavy Materiel Supply | Military and Defence |
| Helmet Mounted Sight | Military and Defence |
| Hour Minute Second | Military and Defence |
| Home Management Service | Networking |
| Hybrid Management Sub-layer | Networking |
| High-mast System | Radio Science |
| Hotel Management Software | Softwares |
| History Memory System | Space Science |
