EPSG:4901

GEOGCS["ATF (Paris)",DATUM["D_ATF",SPHEROID["Plessis_1817",6376523,308.64]],PRIMEM["Paris RGS",2.337208333333333],UNIT["grad",0.01570796326794897]]

+proj=longlat +a=6376523 +b=6355862.933255573 +pm=2.337208333333333 +no_defs 

proj4.defs("EPSG:4901","+proj=longlat +a=6376523 +b=6355862.933255573 +pm=2.337208333333333 +no_defs");

<?xml version="1.0" encoding="UTF-8"?>
 <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-4901">
   <gml:metaDataProperty>
      <epsg:CommonMetaData>
         <epsg:type>geographic 2D</epsg:type>
         <epsg:revisionDate>2007-11-01</epsg:revisionDate>
         <epsg:changes>
            <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2000.070" />
            <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2007.083" />
         </epsg:changes>
         <epsg:show>true</epsg:show>
         <epsg:isDeprecated>false</epsg:isDeprecated>
      </epsg:CommonMetaData>
   </gml:metaDataProperty>
   <gml:identifier codeSpace="OGP">urn:ogc:def:crs:EPSG::4901</gml:identifier>
   <gml:name>ATF (Paris)</gml:name>
   <gml:remarks>ProjCRS covering all mainland France based on this datum used Bonne projection. In Alsace, suspected to be an extension of core network based on transformation of old German system.</gml:remarks>
   <gml:domainOfValidity xlink:href="urn:ogc:def:area:EPSG::1326" />
   <gml:scope>Geodetic survey.</gml:scope>
   <gml:ellipsoidalCS xlink:href="urn:ogc:def:cs:EPSG::6403" />
   <gml:geodeticDatum xlink:href="urn:ogc:def:datum:EPSG::6901" />
</gml:GeodeticCRS>

<?xml version="1.0" encoding="UTF-8"?>
 <gml:GeographicCRS gml:id="ogrcrs201124" xmlns:gml="http://www.opengis.net/gml/3.2">
  <gml:srsName>ATF (Paris)</gml:srsName>
  <gml:srsID>
    <gml:name gml:codeSpace="urn:ogc:def:crs:EPSG::">4901</gml:name>
  </gml:srsID>
  <gml:usesEllipsoidalCS>
    <gml:EllipsoidalCS gml:id="ogrcrs201125">
      <gml:csName>ellipsoidal</gml:csName>
      <gml:csID>
        <gml:name gml:codeSpace="urn:ogc:def:cs:EPSG::">6402</gml:name>
      </gml:csID>
      <gml:usesAxis>
        <gml:CoordinateSystemAxis gml:id="ogrcrs201126" gml:uom="urn:ogc:def:uom:EPSG::9102">
          <gml:name>Geodetic latitude</gml:name>
          <gml:axisID>
            <gml:name gml:codeSpace="urn:ogc:def:axis:EPSG::">9901</gml:name>
          </gml:axisID>
          <gml:axisAbbrev>Lat</gml:axisAbbrev>
          <gml:axisDirection>north</gml:axisDirection>
        </gml:CoordinateSystemAxis>
      </gml:usesAxis>
      <gml:usesAxis>
        <gml:CoordinateSystemAxis gml:id="ogrcrs201127" gml:uom="urn:ogc:def:uom:EPSG::9102">
          <gml:name>Geodetic longitude</gml:name>
          <gml:axisID>
            <gml:name gml:codeSpace="urn:ogc:def:axis:EPSG::">9902</gml:name>
          </gml:axisID>
          <gml:axisAbbrev>Lon</gml:axisAbbrev>
          <gml:axisDirection>east</gml:axisDirection>
        </gml:CoordinateSystemAxis>
      </gml:usesAxis>
    </gml:EllipsoidalCS>
  </gml:usesEllipsoidalCS>
  <gml:usesGeodeticDatum>
    <gml:GeodeticDatum gml:id="ogrcrs201128">
      <gml:datumName>Ancienne_Triangulation_Francaise_Paris</gml:datumName>
      <gml:datumID>
        <gml:name gml:codeSpace="urn:ogc:def:datum:EPSG::">6901</gml:name>
      </gml:datumID>
      <gml:usesPrimeMeridian>
        <gml:PrimeMeridian gml:id="ogrcrs201129">
          <gml:meridianName>Paris RGS</gml:meridianName>
          <gml:meridianID>
            <gml:name gml:codeSpace="urn:ogc:def:meridian:EPSG::">8914</gml:name>
          </gml:meridianID>
          <gml:greenwichLongitude>
            <gml:angle gml:uom="urn:ogc:def:uom:EPSG::9102">2.337208333333333</gml:angle>
          </gml:greenwichLongitude>
        </gml:PrimeMeridian>
      </gml:usesPrimeMeridian>
      <gml:usesEllipsoid>
        <gml:Ellipsoid gml:id="ogrcrs201130">
          <gml:ellipsoidName>Plessis 1817</gml:ellipsoidName>
          <gml:ellipsoidID>
            <gml:name gml:codeSpace="urn:ogc:def:ellipsoid:EPSG::">7027</gml:name>
          </gml:ellipsoidID>
          <gml:semiMajorAxis gml:uom="urn:ogc:def:uom:EPSG::9001">6376523</gml:semiMajorAxis>
          <gml:secondDefiningParameter>
            <gml:inverseFlattening gml:uom="urn:ogc:def:uom:EPSG::9201">308.64</gml:inverseFlattening>
          </gml:secondDefiningParameter>
        </gml:Ellipsoid>
      </gml:usesEllipsoid>
    </gml:GeodeticDatum>
  </gml:usesGeodeticDatum>
</gml:GeographicCRS>

4901=GEOGCS["ATF (Paris)",DATUM["Ancienne_Triangulation_Francaise_Paris",SPHEROID["Plessis 1817",6376523,308.64,AUTHORITY["EPSG","7027"]],AUTHORITY["EPSG","6901"]],PRIMEM["Paris RGS",2.337208333333333,AUTHORITY["EPSG","8914"]],UNIT["grad",0.01570796326794897,AUTHORITY["EPSG","9105"]],AUTHORITY["EPSG","4901"]]

PROJECTION
	"proj=longlat"
	"a=6376523"
	"b=6355862.933255573"
	"pm=2.337208333333333"
	"no_defs"
END

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=longlat +a=6376523 +b=6355862.933255573 +pm=2.337208333333333 +no_defs">
	<Layer srs="+proj=longlat +a=6376523 +b=6355862.933255573 +pm=2.337208333333333 +no_defs">
	</Layer>
</Map>

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 4901, 'EPSG', 4901, '+proj=longlat +a=6376523 +b=6355862.933255573 +pm=2.337208333333333 +no_defs ', 'GEOGCS["ATF (Paris)",DATUM["Ancienne_Triangulation_Francaise_Paris",SPHEROID["Plessis 1817",6376523,308.64,AUTHORITY["EPSG","7027"]],AUTHORITY["EPSG","6901"]],PRIMEM["Paris RGS",2.337208333333333,AUTHORITY["EPSG","8914"]],UNIT["grad",0.01570796326794897,AUTHORITY["EPSG","9105"]],AUTHORITY["EPSG","4901"]]');

GEOGCS["ATF (Paris)",DATUM["Ancienne_Triangulation_Francaise_Paris",SPHEROID["Plessis 1817",6376523,308.64,AUTHORITY["EPSG","7027"]],AUTHORITY["EPSG","6901"]],PRIMEM["Paris RGS",2.337208333333333,AUTHORITY["EPSG","8914"]],UNIT["grad",0.01570796326794897,AUTHORITY["EPSG","9105"]],AUTHORITY["EPSG","4901"]]

[0, 0, (6376523.0, 6355862.933255573, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0), -1]