Military Sealift Command 
Mobile Switching Center 
Manned Spacecraft Center 
Major Subordinate Command 
Maritime Safety Committee 
Major Subordinate Commands 
Mobile Switching Centre 
Meteorological Satellite Center 
Meteorological Service of Canada 
Mobile Servicing Center 
Message Sequence Chart 
Message Switching Center 
Mathematics Subject Classification 
Multiple Systems Coupling 
Macro Selection Compiler 
Manpower Services Commission 
Maritime Sector Commander 
Mass Storage Class 
Master of Science 
Master Sequence Controller 
Materials Service Center 
Medical Service Corps 
Microgravity Smoldering Combustion 
Mine Sweeper, Coastal 
Mission Systems Contract 
Mobile Services Switching Center 
Moding Sequencing and Control 
Multimedia Super Corridor 
Major Subordinate Commander 
Malaysian Multimedia Super Corridor