| HAA | Alif Atoll 
| Others |
| HAA | Haloacedic Acid A
| Others |
| HAA | HaloAcetic Acid
| Others |
| HAA | Haloacetic Acid And
| Others |
| HAA | Hamilton Anderson Associates
| Others |
| HAA | Hampton Athletic Association
| Others |
| HAA | HAN: a language of the United States
| Others |
| HAA | Harvard Alumni Association
| Others |
| HAA | Harvard Athletic Association
| Others |
| HAA | Harvard Athletic Associaton
| Others |
| HAA | Hastings Architecture Associates
| Others |
| HAA | Hasvik, Norway
| Others |
| HAA | Haunted Attraction Association
| Others |
| HAA | Havyaka Association of Americas
| Others |
| HAA | Headrests Adjustable on All Seats
| Others |
| HAA | Health Action Area
| Others |
| HAA | Heavy Anti Aircraft
| Others |
| HAA | Heavy Anti Archiver
| Others |
| HAA | Heavy Anti-Aircraft
| Others |
| HAA | Height Above Airport
| Others |
| HAA | Helicopter Alighting Area
| Others |
| HAA | Hepatitis Associated Antibodies
| Others |
| HAA | Hepatitis Australian Antigen
| Others |
| HAA | Hepatitis- Associated Antigen
| Others |
| HAA | Hepatitis-Associated Antibody
| Others |
| HAA | Hepatitis-Associated Antigen
| Others |
| HAA | Heterocyclic Aromatic Amines
| Others |
| HAA | High Altitude Abort
| Others |
| HAA | High Altitude Airship
| Others |
| HAA | High Altitude Area
| Others |
| HAA | High Altitude Area
| Territory |
| HAA | High Altitude Areas
| Others |
| HAA | Hill Ascent Assist
| Others |
| HAA | Hillsboro Aero Academy
| Others |
| HAA | Hinsdale Adventist Academy
| Others |
| HAA | Hispanics Across America
| Others |
| HAA | Histiocytosis Association of America
| Others |
| HAA | Historic Action Adventure
| Others |
| HAA | Historic Auto Attractions
| Others |
| HAA | Historically Accurate Appearances
| Others |
| HAA | History of Art and Architecture
| Others |
| HAA | Home Acoustics Alliance
| Others |
| HAA | Home Automation Association
| Others |
| HAA | Honda Access America
| Others |
| HAA | Honda Access Asia
| Others |
| HAA | Hormonally Active Agent
| Others |
| HAA | Horror Action Adventure
| Others |
| HAA | Hospice Association of America
| Others |
| HAA | Hospital Activity Analysis
| Others |
| HAA | Houston Apartment
| Others |
| HAA | Houston Apartment Association
| Others |
| HAA | Houston Apartment Association's
| Others |
| HAA | Houston Arts Alliance
| Others |
| HAA | Hsanz Anzsbt Asth
| Others |
| HAA | Hungarian Astronomical Association
| Others |
| HAA | Hungry After All
| Others |