Landing, Cargo, Attack, class/type of ship. LPD – Landing, Personnel, Dock, class/type of ship. LPA – Landing, Personnel, Attack, class/type of ship. LPH – Landing, Personnel, Helicopter, class/type of ship. LPO – Leading Petty Officer LPOD – Last Plane On Deck LRAD – Long Range Acoustic Device LS – Logistics Specialist LSD – Landing Ship, Dock, class/type of ship. LSO – Landing Signal Officer LST – Landing Ship, Tank, class/type of ship. LT – Lieutenant LTJG – Lieutenant Junior Grade M MAA (also meMA) – Master-at-Arms MALS – Marine Aviation Logistics Squadron MC – Mass Communication Specialist MCO – Material Control Officer MCPO – Master Chief Petty Officer MCPON – Master Chief Petty Officer of the Navy (pronounced "Mick Pon") MIDN – Midshipman MIDRATS – Midnight Rations MLCPO – Machinery Division Leading Chief Petty Officer (Submarine) MM – Machinist's Mate MMCO – Maintenance/Material Control Officer MMCPO – Maintenance Master Chief Petty Officer MMN – Machinist's Mate, Nuclear Field MO – Maintenance Officer (pronounced "Moe") MOA – Memorandum of Agreement MOU – Memorandum of Understanding MPA – Main Propulsion Assistant MPA – Military Patrol Craft (P-3 Orion, etc.) MR – Machinery Repairman MRDB – Material Readiness Database MSG – Message MSW – Main Seawater System MT – Missile Technician MTS – Master Training Specialist MU – Musician N NAB – Naval Amphibious Base NAF – Naval Air Facility NALCOMIS – Naval Aviation Logistics Command Management Information System NAMI – Naval Aerospace Medicine Institute NAS – Naval Air Station NAS JRB – Naval Air Station / Joint Reserve Base NATOPS – Naval Air Training and Operational Procedure Standardization NAVAIR – Naval Air Systems Command NAVCOMP – Comptroller of the Navy NAVEDTRA – Chief of Navy Education and Training NAVFAC – Naval Facilities Engineering Command NAVFLIGHTDEMRON – Navy Flight Demonstration Squadron (Blue Angels) NAVMAT – Naval Material Command NAVMILPERSCOM – Navy Military Personnel Command NAVSEA – Naval Sea Systems Command NAVSECGRUACT – Naval Security Group Activity NAVSTA – Naval Station NAVSUBASE – Naval Submarine Base NAVSUP – Naval Supply Systems Command NAVTRA – Chief of Naval Training NAWCAD – Naval Air Warfare Center, Aircraft Division NAWCWD – Naval Air Warfare Center, Weapons Division (formerly Pacific Missile Test Center) NBSD – Naval Base San Diego NC – Navy Counselor NCDU – Navy Combat Demolition Unit NCF – Naval Construction Force (Seabees) NCIS – Naval Criminal Investigative Service NCM – Navy Commendation Medal NCTAMS –