As of May 31, 2023, we have updated our Code of Conduct.

A group that maintains a freely available database with standard codes for coordinate systems, datums, spheroids, units and the like

EPSG is an acronym for European Petroleum Survey Group. The group no longer formally exists, being absorbed into the International Association of Oil & Gas Producers (IOGP) in 2005.

The EPSG Geodetic Parameter Dataset is maintained by the Geodesy Subcommittee of the IOGP Geomatics Committee.

The dataset is a collection of definitions of coordinate reference systems and coordinate transformations which may be global, regional, national or local in application.

The primary EPSG Dataset is maintained in the online registry, from which data may be accessed through a graphic user interface or through a service interface. The online registry contains the most current data. Registry users may query and view the data, generate printable reports and create Well-known Text (WKT) compliant with ISO 19162.

Example outputs:

EPSG:4326 as WKT gives:

GEODCRS["WGS 84",
  DATUM["World Geodetic System 1984",
    ELLIPSOID["WGS 84",6378137,298.257223563,LENGTHUNIT["metre",1.0]]],
  CS[ellipsoidal,2],
    AXIS["latitude",north,ORDER[1]],
    AXIS["longitude",east,ORDER[2]],
    ANGLEUNIT["degree",0.01745329252],
  ID["EPSG",4326]]

EPSG:4326 as GML gives:

<gml:GeodeticCRS xmlns:epsg="urn:x-ogp:spec:schema-xsd:EPSG:1.0:dataset" xmlns:gml="http://www.opengis.net/gml/3.2" xmlns:xlink="http://www.w3.org/1999/xlink" gml:id="epsg-crs-4326">
    <gml:metaDataProperty>
        <epsg:CommonMetaData>
            <epsg:type>geographic 2D</epsg:type>
            <epsg:informationSource>EPSG. See 3D CRS for original information source.</epsg:informationSource>
            <epsg:revisionDate>2007-08-27</epsg:revisionDate>
            <epsg:changes>
                <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2002.151"/>
                <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2003.370"/>
                <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2006.810"/>
                <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2007.079"/>
            </epsg:changes>
            <epsg:show>true</epsg:show>
            <epsg:isDeprecated>false</epsg:isDeprecated>
        </epsg:CommonMetaData>
    </gml:metaDataProperty>
    <gml:metaDataProperty>
        <epsg:CRSMetaData>
            <epsg:projectionConversion xlink:href="urn:ogc:def:coordinateOperation:EPSG::15593"/>
            <epsg:sourceGeographicCRS xlink:href="urn:ogc:def:crs:EPSG::4979"/>
        </epsg:CRSMetaData>
    </gml:metaDataProperty>
    <gml:identifier codeSpace="OGP">urn:ogc:def:crs:EPSG::4326</gml:identifier>
    <gml:name>WGS 84</gml:name>
    <gml:domainOfValidity xlink:href="urn:ogc:def:area:EPSG::1262"/>
    <gml:scope>
        Horizontal component of 3D system. Used by the GPS satellite navigation system and for NATO military geodetic surveying.
    </gml:scope>
    <gml:ellipsoidalCS xlink:href="urn:ogc:def:cs:EPSG::6422"/>
    <gml:geodeticDatum xlink:href="urn:ogc:def:datum:EPSG::6326"/>
</gml:GeodeticCRS>

EPSG:4326 as short report