What does HAO stand for?

Elof Hansson - NCIC firearms make code (NCIC)

Hako - Language code (ETLW)

Hamilton, OH - Location identifier - FAA (FAAL)

Hardin Marine - NCIC boat manufacturer code (NCIC)

Hardin Marine, Anaheim, CA - Manufacturer code for watercraft hull identification number (USCG)

Hardware Action Officer - Military (AABC)

Haute Activite Oxyde (ALPHA)

Health Action Overseas (ADWA)

Hearing Aid Follow-Up and Orientation - Otorhinolaryngology (DAVI)

High Activity Oxide (SAUS)

High Altitude Observatory - Military technology (DDF)

High Altitude Observatory - Research center (RCD)

High-Altitude Observatory - Boulder, CO - National Center for Atmospheric Research

Hip Osteoarthritis - Medicine (MELL)

Home Address Operation (SAUS)

Horticultural Advisory Officer (SAUO)

Hospitals, Administration, and Organizations - British

Hughes Aeronautical Operations (ACAE)

Hydrated Aluminium Oxide (SAUS)

Hydrogenated Anthracene Oil (SAUS)