Message Handling System 
Military Health System 
Microwave Humidity Sounder 
Message Handling Systems 
Message Handling Service 
Master of Health Science 
Master of Health Sciences 
Message Handling Services 
Make haste slowly 
Material Handling System 
Meat Hygiene Service 
Message Handling System/Service 
Military Healthcare System 
Air Memphis 
Macintyre High School 
Macksville High School 
Maclean High School 
macular holes 
Madera High School 
Magnetic Hyperfine Structure 
Magnolia High School 
Mail Handling Service 
Mail Handling System 
Maitland High School 
major histocompatibility system 
Malayan Historical Society 
male homosexuals 
Malibu High School 
malignant hyperpyrexia susceptible 
Malignant hyperthermia susceptibility