| m | Meter |
| m. | mittlere |
| M. | Mile; mille (1,000); Mitte |
| MA | Mean annual; Maritime Administration; Massachusetts |
| MAC | Mapping Applications Center; Mineralogical Assn. of Canada; Mapping Advisory Committee |
| MACA | Ministerio de Asuntos Campesinos y Agropecuarios (Bolivia) |
| MAD | Management Areas Database; Metro Area Disaster GIS (Oregon) |
| MADM | Multiple attributes decision-making |
| MAF | Master address file |
| MAFF | Ministry of Agriculture, Fisheries and Food (U.K.) |
| MAFI | Magyar Allami Foldtani Intezet = Hungarian Geological Inst. |
| MAG | Ministerio de Agricultura y Ganaderia (Costa Rica, Ecuador) |
| MAGE | Map Authoring and Generalisation Expert |
| MAGERT | Map and Geography Round Table (ALA) |
| MAGI | Maryland Automated Geographic Information System |
| MAGIC | Map and Geographic Information Center (Univ. of Conn. and Univ. of New Mexico) |
| MAGSAT | Magnetic Field Satellite (U.S.) |
| MALSCE | Massachusetts Assn. of Land Surveyors and Civil Engineers |
| MAP | Map Analysis Package; Mapping Alliance Program (Space Imaging, Inc.); Market Area Planner (Huff) |
| MAPA | Ministerio de Agricultura, Pesca y Alimentacion (Spain) |
| MAPCAT | Map catalog |
| MAPDS | Ministerio de Agricultura y Pesca, Direccion de Suelos (Uruguay) |
| MAPIS | Map Products Information System |
| MaPKBS | Map Projection Knowledge-based System |
| MAPPS | Management Assn. for Private Photogrammetric Surveyors; Maps, Aerial Photo and Publication System |
| MAPS | Mississippi Assn. of Professional Surveyors; Measurement of Air Pollution from Satellite |
| M.A.P.S. | Microcomputer-based Automated Projection System |
| MAPSAT | Mapping Satellite (U.S.) |
| MAR | Mean annual runoff |
| MARC | Machine Readable Cataloging (LC); Mid-America Remote Sensing Center (Murray State Univ., KY) |
| MARIS | Mississippi Automated Resource Information System |
| MARLS | Missouri Assn. of Registered Land Surveyors; Montana Assn. of Registered Land Surveyors |
| MAS | Millimeterwave Atmospheric Sounder |
| MASC | Map Activity Support Contract |
| Mass. | Massachusetts |
| Mat-Su | Matanuska-Susitna Borough (Alaska) |
| MAT | Medial-axis transformation |
| MATLAB | Matrix Laboratory |
| MAW | Metropolitan area window |
| mB | Millibar |
| MB | Megabyte |
| MBMG | Montana Bureau of Mines and Geology |
| MBPS | Million bits per second |
| MBR | Minimum bounding rectangle |
| MC | Mapping Center |
| MC&G | Mapping, Charting & Geodesy (U.S. Dept. of Defense) |
| MCD | Minor civil division; Major civil division |
| MCDM | Multi-criteria decision-making |
| MCE | Mapping and Charting Establishment (Canada) |
| MCGA | Monochrome/Color Graphics Adapter |
| McIDAS | Map-computer Interactive Data Access System |
| MCIS | Maps and Chart Information System |
| MCM | Mid-continent Mapping Center (USGS) |
| MCO | Mars Climate Orbiter |
| MCS | Master Control Station |
| Md. | Maryland |
| MD | Maryland; Metadata |
| MDA | Monochrome Display Adapter; MacDonald, Dettwiler and Associates, Inc. |
| MDAS | Multispectral Data Analysis System (Bendix Corp.) |
| MDC | Div. de la Cartographie (Morocco) |
| MDD | Mineral Deposits Div., Geological Assn. of Canada |
| MDG | Direction de la Geologie (Morroco) |
| MDGLS | Missouri Div. of Geology and Land Survey |
| MDL | Measurement Devices Ltd.; MicroStation Development Language (Bentley Systems) |
| M.D.M. | Mount Diablo Meridian |
| MDP | Master Data Processor |
| MDR | Minimum Data Recorder |
| MDS | Metadata standards; Multi-dimensional scaling |
| MDSHS | Mount Diablo Surveyors Historical Society |
| MDSD | Mono-Digitizer Stereo-Digitizer |
| MDT | Mountain Daylight Time |
| MDTC | Div. de la Topographie et de la Cartographie (Mauritania) |
| Me. | Maine |
| M.E. | Military Engineer; Mining Engineer |
| ME | Maine; Monoscopic Extraction |
| MECM | Miss~ao de Estudos Cartograficos de Macao |
| MEDEA | Measurements of Earth Data for Environmental Analysis (U.S.) |
| MEDS | Minimum essential data set |
| MEGRIN | Multipurpose European Ground Related Information Network |
| mehr-gesch. | mehrgeschossig |
| MEI | Maps Etc. Inc. |
| MEIS | Multispectral Electrooptical Imaging Sensor |
| MEM | Ministry of Energy and Minerals (Tanzania) |
| MEMPR | Ministry of Energy, Mines and Petroleum Resources (British Columbia) |
| MENR | Ministry of Energy and Natural Resources (Trinidad and Tobago) |
| MEOW | Mono-Extraction Orthophoto Workstation |
| MER | Minist`ere de l'Energie et des Ressources (Quebec) |
| MERES | Mineral and Energy Resources Exploration Satellite (Japan) |
| MERIS | Medium Resolution Imaging Spectrometer |
| MERRA | Michigan Energy and Resources Research Association |
| MESSR | Multispectral Electronic Self-Scanning Radiometer |
| METSAT | Meteorological Satellite |
| MEWS | Mono-Extraction Workstation |
| MFC | Map Feature Coding |
| MFGDP | Manual of Federal Geographic Data Products |
| MFLOPS | Million Floating Points Operations Per Second |
| MFS | Maine Forest Service |
| MGB | Mississippi Bureau of Geology |
| MGE | Microstation GIS Environment (Intergraph); Modular GIS Environment |
| MGG | Marine Geology and Geophysics Report |
| MGIS | Micro Geographic Information System |
| MGS | Maine Geological Survey; Maryland Geological Survey; Minnesota Geological Survey; Mars Global Surveyor (satellite) |
| MGRS | Military Grid Reference System |
| MGSD | Michigan Geological Survey Div. |
| MGSSSR | Ministerstvo Geologii SSSR |
| MH | Ministry of Housing (Bahrain) |
| M.H. | Meierhof = dairy farm |
| MHTD | Missouri Highway and Transportation Dept. |
| MHW | Mean High Water |
| MHz | Megahertz |
| Mi. | Mile(s) |
| MI | Michigan; Military Intelligence; Miscellaneous Investigations (map) |
| MIAS | Multispectral Image Analysis System |
| Mich. | Michigan |
| MIEM | Minist`ere de l'Industrie et de Mines (Malagasy Republic) |
| MIF | Main Image File; MapInfo Interchange Format |
| Mil. | Military |
| MIL | Map and Imagery Laboratory (Univ. of Calif., Santa Barbara); Milli-inch (1 thousandth of an in.) |
| MILSTRIP | Military Standard Requisitioning and Issue Procedures (USDMA) |
| MILUS | Multiple Input Land Use System (JPL software) |
| MIME | MultiPurpose Internet Mail Extension |
| Min. | Minute |
| Min. E. | Mineral Engineer; Mining Engineer |
| Minn. | Minnesota |
| MIO | Map Information Office |
| MIPS | Map and Image Processing System; Million Instructions Per Second; Mini-Image Processing System |
| MIS | Management Information System; Map Information System |
| MISR | Macaulay Institute for Soil Research |
| Miss. | Mississippi |
| MITE | Megapixel Imaging Technology |
| MITES | Miniature Interferometer Terminals for Earth Survey |
| ML | Master Library |
| MLA | Multi-linear array |
| MLHD | Maximum likelihood (decision functions) |
| MLMIC | Minnesota Land Management Information Center |
| MLMIS | Minnesota Land Management Information System |
| MLRA | Major Land Resource Areas |
| MLTA | Maine Land Title Assn. |
| MLW | Mean low water |
| MMKS | Mjetve Mesimore Kulturore e Sportive "Hamid Shijaku" (Albania) |
| MMOI | Mathematical Mode of Inquiry |
| MMQ | Metric Map Questionnaire |
| MMS | Metropolitan Map Series; Minerals Management Service (U.S.); Multi-Mission Modular Spacecraft (U.S.) |
| MMSD | Metric Mapping Support Data |
| MN | Magnetic north; Mine; Minnesota |
| MNFS | Minor frame synchronization |
| MNS | Multi-Navigator System (Brunton) |
| Mo. | Missouri |
| MO | Magnetic-optical disc; Member organization; Missouri; Model orientation |
| MOA | Minute of angle |
| MODM | Multiple objectives decision-making |
| MODN | Module name |
| MODS | Moderate Resolution Imaging Spectrometer |
| MOLDS | Inst. for Modernization of Land Data Systems |
| MOMS | Modular Optoelectric Multispectral Scanner |
| Mont. | Montana |
| M.O.P. | Ministerio de Obras Publicas |
| MOPU | Ministerio de Obras Publicas y Urbanismo (Spain) |
| MoRAP | Missouri Resource Assessment Partnership |
| MOS | Marine Observation Satellite; Multispectral Optoelectric Scanner |
| MOSS | Map Overlay and Statistical System |
| MOST | Moving Objects Spatio-Temporal |
| MOUG | Map Online Users Group |
| MP | Measuring point |
| MPE | Map Publishing Environment |
| MPLIS | Multipurpose land information system(s) |
| Mpls. | Minneapolis |
| MPO | Multiproduct operation |
| MPP | Multi-spectral scanner preprocessor |
| MPRD | Modified Proportional Radial Displacement |
| MPRM | Ministry of Petroleum and Mineral Resources (Saudi Arabia) |
| MPWUPH | Ministry of Public Works, Urban Planning and Housing (Djibouti) |
| MR | Monoscopic revision |
| MRAC | Musee Royale de l'Afrique Centrale |
| MRB | Missouri River Basin |
| MRBC | Missouri River Basin Commission |
| MRC | Mississippi River Commission; Map Reference Code (USGS) |
| MRD | Mineral Resources Div. (Manitoba); Mineral Resources Dept. (Fiji); McCloud Ranger District |
| MRDB | Mapping Requirements Data Base System |
| MRI | Metadata Reference Information; Mediamark Research Inc. |
| MRIR | Medium Resolution Infrared Radiometer |
| MRLU | Map Reproduction and Liaison Unit |
| MRMS | Maritime Resources Management Service |
| MRS | Multispectral Resource Sampler |
| MrSID | Multiresolution Seamless Image Database |
| MRSA | Major River Systems Analysis |
| MRSH | Marsh |
| MRWS | Monoscopic Revision Workstation |
| ms. | Manuscript |
| MS | Manuscript; Mean seasonal; Milli-second; Microsoft Corp.; Monochromatic Scanner; Mississippi |
| MSA | Metropolitan statistical area; Mineralogical Society of America; Maritime Safety Agency (Japan) |
| MSC | Map Society of California; Mapping Science Committee (NRC) |
| MSD | Mapping support data; Malawi Dept. of Surveys; Mauritius Survey Dept. |
| MSDO | Mapping Support District Office |
| MS-DOS | MicroSoft Disc Operating System |
| MSE | Mean square error |
| MSEDB | Mapping Sciences Education Data Base |
| MSIA | Mapping Sciences Inst., Australia |
| MSIRI | Mauritius Sugar Industry Research Inst. |
| MSIS | Map Separates Information System; Model State Information System |
| MSL | Mean sea level |
| MSLS | Maine Society of Land Surveyors |
| MSP | Multispectral photography |
| .MSP | Microsoft Paint format |
| MSPE | Missouri Society of Professional Engineers |
| MSPS | Michigan Society of Professional Surveyors; Minnesota Society of Professional Surveyors |
| MSR | Minimal Spatial Representation |
| MSRLS | Michigan Society of Registered Land Surveyors |
| MSS | Multispectral Scanner; Maryland Society of Surveyors |
| MST | Mountain Standard Time |
| MSTS | Map Separates Tracking System |
| MSV | Model and Scenario Visualization |
| Mt. | Mount; Mountain; Mont |
| MT | Mountain; Montana |
| MTA | Major Trading Areas (FCC) |
| MTAE | Maden Tetkik ve Arama Enstitutu (Turkey) |
| MTC | Ministerio de Transporte y Comunicaciones (Venezuela) |
| MTF | Modulation transfer function |
| MTLT | Minimum Total Length Triangulation |
| Mtn. | Mountain |
| MTP | MSS Telemetry Processor |
| MTPE | Mission to Planet Earth (NASA) |
| MTS | Mountains; Maine Technical Source |
| MTSAT | Multi-Functional Transport Satellite (Japan) |
| MTT | Mobile Training Teams (USDMA) |
| MTU | Magnetic tape unit |
| MUID | Map Unit ID (Identification) |
| MUIR | Map Unit Interpretations Record (US NRCS) |
| MURB | Minister fur Umwelt, Raumordnung und Bauwesen (Saarland) |
| MW | Megawatt |
| M.W. | Mittelwasser |
| MWDI | Master Water Data Index |
| MWF | Map Window File |
| MWT | Minimum Weight Triangulation |