| C | Cartography; Celsius (degrees) |
| ca. | Circa |
| CA | California |
| C/A | Coarse-Acquisition (code) |
| CAA | Civil Aeronautics Administration (U.S.); Civil Aviation Authority (Great Britain) |
| CAAD | Cartographic and Architectural Archives Div., National Archives of Canada |
| CAC | Center for Advanced Computation (Univ. of Illinois); Compressed Aeronautical Chart (U.S. government) |
| CACS | Canadian Active Control System |
| CAD | Computer-aided drafting; Computer assisted design |
| CADD | Computer-aided design and drafting |
| CADMAP | Computer-aided drafting, mapping, and photogrammetry |
| CADRG | Compressed ADRG |
| CAFF | Conservation of Arctic Flora and Fauna |
| CAFM | Computer-aided facility management |
| CaGIS | Cartography and Geographic Information Science (journal)); Cartography and Geographic Information Systems (journal) |
| CAGIS | Cartography and Geographic Information Society |
| Cal. | California |
| Calif. | California |
| CALMIT | Center for Advanced Land Management Information Technologies (Univ. of Nebraska-Lincoln) |
| CALS | Connecticut Assn. of Land Surveyors; Computer-aided acquisition and logistic support; Computer Assisted Land Survey System (SPDK) |
| CALTRANS | California Dept. of Transportation |
| CAM | Computer aided mapping |
| CAMA | Computer-aided mass appraisal system (Montana) |
| CAMEO | Computer-Aided Management of Emergency Operations System (U.S.) |
| CAMFER | Center for the Assessment & Monitoring of Forest & Environmental Resources (Univ. of Calif., Berkeley) |
| CanSIS | Canadian Soil Information System |
| CANSPACE | Canadian Space Geodesy Forum |
| CAP | Cooperative Agreements Program (FGDC) |
| CAPDU | Canadian Assn. of Public Data Users |
| CAR | Curriculum, Accreditation and Registration Committee (ACSM); Central African Republic |
| CARES | Center for Agricultural, Resource, and Environmental Systems (Univ. of Missouri) |
| CARS | Computer-Assisted Reproduction; Center for Applications of Remote Sensing (Oklahoma State Univ.) |
| CASA | Centre for Advanced Spatial Analysis (Univ. College, London) |
| CASE | Computer-Aided Software Engineering |
| CASS | Coding and Accuracy Support System (USPS) |
| CAT | Computer Assisted Thermography |
| CATS | Consequences Assessment Tool Set (FEMA) |
| CAVA | Cartographic and Audio-Visual Archives Div. = Div. des archives cartographiques et audio-visuelles (DACA), National Archives of Canada |
| CAZRI | Central Arid Zone Research Institute |
| CB | Column builder |
| C.B. | Hollow concrete or cement block construction |
| CBD | Central business district |
| CBEP | Community-Based Environmental Protection (USEPA program) |
| CBET | Concrete block enclosed elevator |
| CBI | China Burma India Theatre of Operations (WW II) |
| CBL | Centraal Bureau Luchtkartering (Suriname); Calibration base line |
| cbm | Kubikmeter (cubic meter) |
| CBN | Cooperative Base Network |
| CBP | Chesapeake Bay Project |
| C. BR | Concrete, lime, cinder or cement brick |
| CBS | Community Base Station |
| CBWE | Corn Blight Watch Experiment |
| CC | Cartographic Catalog |
| CCA | Canadian Cartographic Assn. |
| CCAP | Competative Cooperative Agreements Program (U.S.) |
| CCBCCM | Canadian Committee for the Bibliographic Control of Cartographic Materials |
| CCC | Canadian Committee on Cataloging |
| CCCELS | California Council of Civil Engineers and Land Surveyors |
| CCD | Census county division; Computer Center Div. (USGS); Charged couple device; Charged-coupled device; Charge-coupled device |
| CCELC | Canada Committee on Ecological Land Classification |
| CCGE | Canadian Council on Geographic Education |
| CCGM | Center for Computing Graphics (Delft Univ. of Technology) |
| CCIG | Centre canadien d'information sur la geoscience |
| CCID | Chain component ID |
| CCISA | Congress of Cartographic Information Specialist Associations |
| CCITT | International Telegraph and Telephone Consultative Committee |
| CCLS | Canadian Council of Land Surveyors |
| CCM | Canada Centre for Mapping |
| CCNS4 | Computer Controlled Navigation System (E. Coyote Enterprises, Inc.) |
| CCRS | Canada Centre for Remote Sensing |
| CCT | Computer Compatible Tape; Centro de Ciencia Tropical |
| CD | Compact disc; Conservation Div. (USGS); Committee Draft (ISO) |
| CDA | Colorado Dept. of Agriculture |
| CDC | California Dept. of Conservation; Control Data Corporation |
| CD-CINC | CD-ROM Consistent Interface Committee (U.S.) |
| CDED | Canadian Digital Elevation Data |
| CDF | Cumulative distribution function; California Dept. of Forestry |
| CDFG | California Dept. of Fish and Game |
| CDH | Communications and data handling |
| CDi | Compact Disk interactive |
| CDIS | Coordinated Design and Information System |
| CDMG | California Div. of Mines and Geology |
| CDN | Coordinates, definitions and notations |
| CDOW | Colorado Division of Wildlife |
| CDOWG | CD-ROM Data Origination Working Group (U.S.) |
| CDP | Cartographer Development Program; Census designated place; Colorado Division of Planning |
| .CDR | CorelDraw format |
| CD-R | Compact disk-recordable |
| CD-ROM | Compact disk-read only memory |
| CDRS | Collaborative Digital Reference Service |
| CDS | Catalogue of Data Sources |
| CDT | Computer display terminal; Central Daylight Time; Constrained Delaunay triangulation |
| CDTED | Compressed digital terrain elevation data |
| CDV | Cartographic data visualizer |
| CD-W | Compact disk-- re-writable |
| CDWR | California Dept. of Water Resources |
| CE | Corps of Engineers |
| C.E. | Civil Engineer |
| CEAL | Centro Editor de America Latina |
| CEAO | County Engineers Association of Ohio |
| CEBAF | Continuous Electron Beam Accelerator Facility |
| CECO | Consulting Engineers Council of Ohio |
| CECSVB | Comit pour l'Etablissement de la Carte des Sols et de la Vegetation de la Belgique |
| CECW | Consulting Engineers Council of Washington |
| CEDAC | Comprehensive Economic Data Atlas of China |
| CEDARE | Centre for Environment and Development for the Arab Region and Europe |
| CEDD | Committee on the Exchange of Digital Data |
| CEE | Comite Estatal de Estadisticas (Cuba) |
| CEGET | Centre d'Etudes de Geographie Tropical (Bordeaux) |
| CELSOC | Consulting Engineers and Land Surveyors of California |
| Cem. | Cemetery |
| CEMA | Consumer Electronics Manufacturers Assn. |
| CEN | Comite europeen de normalization electronique |
| CENREN | Centro de Recursos Naturales (El Salvador) |
| CENTA | Centro Nacional de Tecnologia Agropecuaria (El Salvador) |
| CENTAUR | Civil Engineering Technologies for Automatic Roadmaking (DSNP) |
| CEO | European Centre for Earth Observation |
| CEONet | Canadian Earth Observation Network |
| CEP | Celestial Ephemeris Pole |
| CERCLIS | Comprehensive Environmental Response, Compensation, and Liability Information System (US EPA) |
| CERCO | Comite Europeen de Responsibles de la Cartographie Officielle |
| CERD | Catalog of Environmental Resource Data |
| CERES | California Environmental Resource Evaluation System |
| CERCG | Centre d'Etudes et de Realisations Cartographiques Geographiques (France) |
| CERR | Centre d'Ecologie des Ressources Renouvelables (France) |
| CES | Committee on Earth Sciences |
| CET | Commission on Education and Training (IGA) |
| CETENAL | Comision de Estudios del Territorio Nacional (Mexico) |
| CEU | Continuing education unit |
| CFCC | Census Feature Class Code |
| CFF | Cartographic Feature File |
| C.G. | Coast Guard |
| CGA | Color Graphics Adaptor |
| CGC | Commission geologique du Canada |
| CGDB | Central Geographic Data Base |
| CGDI | Canadian Geospatial Data Infrastructure |
| CGI | Computer Graphics Interface; Common gateway interface; Center for Geographic Information |
| CGIC | Canadian Geoscience Information Centre |
| CGIS | Center for GIS (Qatar) |
| .CGM | Computer graphics metafile |
| CGMW | Commission for the Geological Map of the World |
| CGNHS | Connecticut Geological and Natural History Survey |
| CGPM | Conference General des Poids et Mesures |
| C&GS | Coast and Geodetic Survey (U.S.); Commercial & Government Systems (Kodak) |
| CGS | Civil GPS Service; Coast and Geodetic Survey (U.S.); Colorado Geological Survey |
| CGSB | Canadian General Standards Board |
| CGSIC | Civil GPS Service Interface Committee |
| CGSICO | Civil GPS Service Interface Committee |
| CGU | Canadian Geophysical Union |
| CGW | Computer Graphics World (journal) |
| CH | Chief Hydrologist; Church; Chapel |
| CHEEC | Center for the Health Effects of Environmental Contamination (Univ. of Iowa) |
| CHEST | Combined Higher Education Software Team (UK) |
| CHGIS | China Historical Geographic Information System (Harvard University) |
| CHIA | Cumulative Hydrologic Impact Assessment |
| CHNM | Marine channel |
| CHS | Canadian Hydrographic Service |
| CI | Compass and inclinometer |
| CIA | Central Intelligence Agency (U.S.) |
| CIAF | Centro de Investigaciones en Percepcion Remota |
| CIAS | CD-ROM Index Architecture Specification Working Group (U.S.) |
| CIACER | Centro de Investigacion y Aplicacion de Sensores Remotos (Bolivia) |
| CIB | Controlled image base |
| CIBESA | Cartografica Iberica S.A. |
| CICAEDAS | Committee Investigating Cartographic Entity, Definitions, and Standards |
| CIDAMM | Centro de Informacion y Documentacion del Area Metropolitana de Madrid |
| CIE | Iompair Eireann Coras; Classified image editor |
| CIESIN | Consortium for International Earth Science Information Network |
| CIG | Canadian Inst. of Geomatics; Climate Interest Group; Centro de Investigaciones Geotecnicas (El Salvador) |
| CIGF | Centre d'Information Geographique et Fonci`ere Ministre de l'Energie et des Ressources, Quebec) |
| CIGNET | Cooperative International GPS Network |
| CIKM | Conference on Information Knowledge Management |
| CIM | Collection insertion map; Council on Information Management (Virginia) |
| CIMIS | California Irrigation Management Information System |
| CINDI | Center for Integration of Natural Disaster Information (USGS) |
| CIO | Central Imagery Office (U.S.) |
| CIP | Contour Interpolation Program; Canadian Institute of Planners |
| CIR | Color infrared |
| CIRSS | California Integrated Remote Sensing System |
| CIS | Canadian Inst. of Surveying; Color Imaging Systems (Barneyscan Corp.) |
| CISD | Cook Islands Dept. of Survey |
| CISIG | Conservational International GIS |
| CISM | Canadian Inst. of Surveying and Mapping |
| CIST | Centre d'information sur les sciences de la Terre (Canada) |
| CITYG | City Graphic |
| CIU | Central Interpretation Unit (Royal Air Force, Great Britain) |
| CK-PL | Check plotter |
| CLD | Center line data |
| CLDB | Common Land Data Base |
| CLDS | Canada Land Data System(s) |
| CLI | Canada Land Inventory |
| CLID | Class identifier |
| CLIRSEN | Remote Sensing Center (Ecuador) |
| Clk. | Clerk |
| CLL | Corrected line length |
| CLOMA | Confidential letters of map amendment |
| CLS | Canada Lands Surveyor |
| CLSA | California Land Surveyors Assn. |
| CLSR | Canada Lands Surveys Records |
| CLUMP | Canada Land Use Monitoring Program |
| cm | Centimeter |
| CM | Cartographic material; Configuration management |
| CMA | Census Metropolitan Area (Statistics Canada); Central Mapping Agency (New South Wales) |
| CMAS | Circular Mean Accuracy Standard |
| CMCC | California Mapping Coordinating Committee |
| CMD | Current meter digitizer; Command |
| CMEDS | Comprehensive Mapping and Engineering Data System (LES) |
| CMI | Corvallis Microtechnology Inc. |
| CMIB | Controlled multispectral image base |
| CMO | Canada Map Office |
| CMOTS | Cartographic Material Order and Tracking System (USGS) |
| CMP | Coastal Mapping Program; Camp |
| CMS | California Map Society; Clay Minerals Society |
| CMSA | Consolidated metropolitan statistical area |
| CMSDU | Commission on Map Use and Spatial Data Use (ICA) |
| CMSM | Committee on Marine Surveying and Mapping |
| CMT | Corvallis Microtechnology Inc. |
| C&MT | Communication & Measurement Technologies Ltd. |
| CMYK | Cyan-magenta-yellow-black |
| CNA | Comiss~ao Nacional do Ambiente (Portugal) |
| CNIDR | Center for Networked Information Discovery and Retrieval (USA) |
| CNES | Centre National d'Etudes Spatiales (France) |
| CNEXO | Centre National pour l'Exploitation des Oceans (France) |
| CNFL | Confluence |
| CNI | Coalition for Networked Information |
| CNIG | Centro Nacional de Informac~ao Geografica = Portuguese National Center for Geographic Information |
| CNR | Consiglio Nazionale delle Richerche (Italy) |
| CNRA | Commission on National and Regional Atlases (ICA) |
| CNRG | Centre National de Recherches Geomorphologiques (Belgium) |
| CNROA | Centro Nacional de Reconhecimento e Ordenamento Agrario (Portugal) |
| CNRS | Centre National de Recherches Scientifique (France) |
| CNRST | Centre National de la Recherche Scientifique et Technologique (Burkina Faso) |
| CNSTAT | Committee on National Statistics (U.S.) |
| Co. | Company; County |
| CO | Cartometric operations; Colorado |
| COBOL | Common Business Oriented Language |
| COBRIG | Council of British Geography |
| COE | Corps of Engineers |
| COEB | Coastal and Estuarine Oceanography Branch (US NOS) |
| COFPAES | Committee on the Federal Procurement of Architect and Engineer Services |
| COFRS | Chinese Operational Earth Resources Satellite |
| COG | Council of Governments |
| COGO | Coordinate geometry |
| C.O.I. | Office of Coordinator of Information (U.S.) |
| col. | Color; colored |
| Col. | Colonel; Colorado |
| COL | Agricultural colony |
| COLD | Computer Output to Laser (optical) Disc |
| Com. | Committee; Commission; Commodore |
| COM | Component Object Model (Microsoft) |
| COMAP | Continuous area pattern mapping |
| Comdg. | Commanding |
| COMIS | Cartographic Operations Management Information System |
| COMPAS | Coastal Ocean Management, Planning and AssessmentSystem |
| COMSAT | Communications Satellite (corp.) |
| CONC. | Concrete or reinforced concrete construction |
| Cong. | Congress |
| Conn. | Connecticut |
| CONRIM | Committee on Natural Resource Information Management(Alaska) |
| CONUS | Continental United States |
| COP/BOP | City of Portland Bureau of Planning |
| CORBA | Common Object Request Broker Architecture |
| CORC | Cooperative Online Resource Catalog (OCLC) |
| Corp. | Corporal; Corporation |
| CORS | Continuously operated reference station(s); Continuously operating GPS reference stations |
| CORSE | Conference on Remote Sensing Education |
| COS | Central Office of Statistics (Malta) |
| COSMIC | Computer Software Management and Information Center |
| COSML | Committee on Southern Map Libraries |
| COSPAR | Committee on Space Research |
| COTS | Commercial-off-the-shelf |
| COVIS | Commonwealth of Virginia Information Systems |
| CP | Cartographic Perspectives (journal); color printer |
| CPFS | Colorado Plateau Field Station (USGS) |
| CPH | Cartographic Publishing House (China) |
| CPID | Composite ID |
| CPLAR | Community Perspectives on Land and Agrarian Reform (South Africa) |
| CPLC | Court of Private Land Claims |
| CPS | Characters per second; Contour plotting system; Cartographic production system |
| CPU | Central processing unit |
| CR | Central Region; Coordinate reader |
| CRADA | Cooperative Research and Development Agreement (U.S) |
| CRAG | Columbia Region Association of Governments |
| CRAIGES | Cartographic Reproduction and Interactive Graphic Editing System |
| CRBT | Centre de Recherches Biologiques Tropicales (Algeria) |
| CRESP | Consortium for Risk Evaluation with Stakeholder Participation (U.S.) |
| CRG | Centre de Recherche en Geomatique (Universite Laval) |
| CRIB | Computerized Resources Information Bank |
| CRISTA | Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere |
| CRKT | Tidal creek |
| CRL | Cartographic research laboratory |
| CRM | Customer relationship management |
| CRN | Canadian Road Network |
| CRPD | City Real Property Database |
| CRREL | Cold Region Research and Engineering Laboratories |
| CRTR | Crater |
| CRSC | California Remote Sensing Council |
| CSDGM | Content Standard for Digital Geospatial Metadata |
| CSDMS | Centre for Spatial Database Management and Solutions |
| CRSS | Canadian Remote Sensing Society |
| CRT | Cathode ray tube |
| CS | Color scanner; Cubic splines |
| CSAA | California State Automobile Association |
| CSAC | Census Statistical Area Committee (U.S.) |
| CSAV | Czechoslovak Academy of Sciences |
| CSC | Computer Sciences Corporation; Commercial Space Center (NASA) |
| CSDGM | Content Standard for Digital Geospatial Metadata (USA) |
| CSFS | Colorado State Forest Service |
| CSG | Cartography Special Group, Assn. of American Geographers; Council of State Governments |
| CSIN | Computer Systems Information Network |
| CSIP | Continental Scale International Project |
| CSIR | Council for Scientific and Industrial Research |
| CSIRO | Commonwealth Scientific and Industrial Research Organization (Australia) |
| CSIC | Consejo Superior de Investigaciones Cientificas (Spain) |
| CSISS | Center for Spatially Integrated Social Sciences (UCSB) |
| CSML | Committee on Southern Map Libraries |
| CSOC | Consolidated Space Operations Center |
| CSP | Conformal Space projection |
| CSPA | Council of State Planning Agencies |
| CSPG | Canadian Society of Petroleum Geologists |
| CSRS | Canadian Spatial Reference System |
| CST | Central Standard Time; Chicago Steel Tape Co.; Coast; Certified Survey Technician |
| Ct. | Court |
| CT | Census tract; Connecticut |
| CTC | Cartoteca de Catalunya; Cooperating Technical Communities |
| CTCUQ | Commission de transport de la Communaute urbaine de Quebec |
| CTD | Chief, Topographic Division; Conductivity-temperature-depth |
| CTI | Critical Technologies Inst. (RAND Corp.) |
| CTL | Cartographic Technology Lab. |
| CTOG | Contour to Grid |
| CTS | Communications Technology Satellite (Canadian); Conventional terrestrial system |
| CUAC | Cartographic Users Advisory Council (U.S.) |
| CUET | Cuesta |
| CUGiK | Centralny Urzad Geodezji i Kartografii (Poland) |
| CUR | Council on Undergraduate Research |
| CUSEC | Central United States Earthquake Consortium |
| CUSMAP | Conterminous United States Minerals Assessment Plan |
| CWRA | Canadian Water Resources Program |
| CWS | Cartographic workstation |
| CYP | Cape York Peninsula |
| CYPLUS | Cape York Peninsula Land Use Strategy |
| CZCS | Coastal Zone Color Scanner |
| CZM | Coastal Zone Management (U.S. federal act of 1972) |