web-server/doc/en/user/source/services/wfs/axis_order.rst

.. _wfs_basics_axis:

Axis ordering
=============

The definition of a spatial reference system includes an indication of the axis order used to interpret the coordinates. There are a number of projected spatial reference systems defined in `north/east` order in the formal ``EPSG`` definition, but are interpreted as being in ``east/north`` order by earlier versions of the ``WFS`` protocol.

* ``WFS 1.0.0``: Provides geographic coordinates in ``east/north`` and may not be trusted to respect the EPSG definition axis order.

* ``WFS 1.1.0``: Respects the axis order defined by the EPSG definition.

* ``WFS 2.0.0``: Respects the axis order defined by the EPSG definition.

Forcing content into ``east/north`` order was intended to be easier for developers where computer displays are defined with an `x/y` order. However this decision has introduced no end of confusion, and was corrected in later versions of ``WFS``.

.. note:: Some spatial reference systems, for example polar stereographic, do not have an ``east`` or ``west`` as they have a pole in the middle of the axis.

These differences may cause difficulties when clients switch between different ``WFS`` versions. To minimize confusion and increase interoperability, GeoServer has adopted the following guidelines when specifying spatial reference systems to avoid ambiguity.

.. list-table::
   :widths: 50 25 25
   :header-rows: 1

   * - Representation
     - Axis order
     - Interpretation
   * - ``EPSG:4326``
     - longitude/latitude
     - assumption
   * - ``http://www.opengis.net/gml/srs/epsg.xml#xxxx``
     - longitude/latitude
     - strict
   * - ``urn:x-ogc:def:crs:EPSG:xxxx``
     - latitude/longitude
     - strict
   * - ``urn:ogc:def:crs:EPSG::4326``
     - latitude/longitude
     - strict

SRSList Axis Order
------------------

To compare the spatial reference system definition for ``EPSG:4326``:

#. Navigate :menuselection:`Demos --> SRS List` page and search for :kbd:`4326`.

#. Compare the formal `EPSG` definition of `WGS84`:

   .. figure:: img/wgs84-epsg-description.png
   
      WGS84 EPSG definition

#. With the internal definition of `WGS84`:

   .. figure:: img/wgs84-internal-description.png
   
      WGS84 Internal definition

The same approach can be used to check the definition of any spatial reference system supported by GeoServer.

.. note:: The formal ``EPSG`` definition provides the axis-order used to interpret coordinate values. GeoServer uses an internal representation that does not always respect the ``EPSG`` provided axis order.

   In the example above ``EPSG:4326`` is defined with a `north/east` axis order, while the internal representation has ``east/north`` order.

   The startup option ``-Dorg.geotools.referencing.forceXY=true`` is used to configure GeoServer to prefer an internal representation in `east/north` axis order. We recommend the default value of ``true`` to match a wide range of clients that make this assumption.

Layer Axis Order
----------------

The default data directory includes the following dataset illustrating this challenge:

* :file:`shapefile/states.shp``: Data stored in x/y order::
  
    MULTIPOLYGON (((-121.664154 38.169369,-121.781296 38.066856, ...
  
* :file:`shapefiles/states.prj` ::
   
     GEOGCS["GCS_WGS_1984",DATUM["WGS_1984",SPHEROID["WGS_1984",6378137,298.257223563]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]
  
  Published as ``topp:states`` with Spatial Reference System ``EPSG:4326``.

To review how this layer has been published:

#. Navigate to the :guilabel:`Edit Layer` page for ``topp:states``.

#. Locate :guilabel:`Native SRS` and click on the :guilabel:`GCS_WGS_1984` link to show how GeoServer interpreted the :file:`PRJ` file above.
  
   The :file:`PRJ` did not provide an axis-order and GeoSever has filled in an assumption. This describing the data in `x/y` order which matches our data and we could use it unmodified.
   
   .. figure:: img/native_srs.png
      
      Native SRS for topp:states

#. Locate :guilabel:`Declared SRS` and click on :guilabel:`EPSG:WGS 84...` link to see the definition used to publish this content.
   
   This is the internal definition of ``EPSG:4326`` as shown in the SRSList above, which also describes the data in `x/y` order matching our data. This definition provides slightly more readable names along with additional  ``AUTHORITY`` information that may be helpful to client applications.
   
   .. figure:: img/declared_srs.png
      
      Declared SRS for topp:states
   
#. The :guilabel:`SRS Handling` is set to ``Force declared`` to completely ignore the provided :guilabel:`Native SRS` definition and use the :guilabel:`Declared SRS`.

   .. figure:: img/srs_handling.png
      
   Force declared SRS handling for topp:states

WFS 1.0 Axis Order
------------------

**GetCapabilities** describes ``topp:states`` using:

http://localhost:8080/geoserver/ows?service=wfs&version=1.0.0&request=GetCapabilities

.. code-block:: xml

    <FeatureType><Name>topp:states</Name>
      <Title>USA Population</Title>
      <Abstract>This is some census data on the states.</Abstract>
      <Keywords>census, united, boundaries, state, states</Keywords>
      <SRS>EPSG:4326</SRS>
      <LatLongBoundingBox minx="-124.731422" miny="24.955967" maxx="-66.969849" maxy="49.371735" />
    </FeatureType> 
   
WFS 1.0 describes the latitude / longitude bounds with the understanding that you will associate `minx` and `maxx` with longitude, and also `miny` and `maxy` with latitude.

WFS 1.0 *GetFeature* request defaults to GML2 output, and the default ``EPSG:4326`` spatial reference system used to publish the layer:

* WFS 1.0 Default: http://localhost:8080/geoserver/ows?service=WFS&version=1.0.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1

  The GML2 output uses ``http://www.opengis.net/gml/srs/epsg.xml#4326`` reference, with data in x/y order:

  .. code-block:: xml

     <gml:MultiPolygon srsName="http://www.opengis.net/gml/srs/epsg.xml#4326">
       <gml:polygonMember>
         <gml:Polygon>
           <gml:outerBoundaryIs><gml:LinearRing>
             <gml:coordinates decimal="." cs="," ts=" ">
               -88.071564,37.51099 -88.087883,37.476273

WFS 1.0 output format GML3
``````````````````````````

* GML3.1 (default ``EPSG:4326``):
  
  http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.0.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1&outputFormat=gml3

  GML3 output uses ``http://www.opengis.net/gml/srs/epsg.xml#4326`` reference, with data in x/y order:
  
  .. code-block:: xml
  
     <gml:MultiSurface srsName="http://www.opengis.net/gml/srs/epsg.xml#4326">
       <gml:surfaceMember>
         <gml:Polygon>
           <gml:exterior>
             <gml:LinearRing>
               <gml:posList>
                 -88.071564 37.51099 -88.087883 37.476273

* GML3.1 reproject to ``EPSG:4326``
  
  http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.0.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1&outputFormat=gml3&srsName=urn:x-ogc:def:crs:EPSG:4326
  
  GML3 output uses ``http://www.opengis.net/gml/srs/epsg.xml#4326`` reference, with data in x/y order:
  
  .. code-block:: xml
  
     <gml:MultiSurface srsName="http://www.opengis.net/gml/srs/epsg.xml#4326">
       <gml:surfaceMember>
         <gml:Polygon>
           <gml:exterior>
             <gml:LinearRing>
               <gml:posList>
                 -88.071564 37.51099 -88.087883
  
* GML 3.1 reproject to ``urn:x-ogc:def:crs:EPSG:4326``
  
  http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.0.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1&outputFormat=gml3&srsName=urn:x-ogc:def:crs:EPSG:4326
  
  GML3.1 output using ``urn:x-ogc:def:crs:EPSG:4326`` reference and data in y/x order:
  
  .. code-block:: xml
     
     <gml:MultiSurface srsName="urn:x-ogc:def:crs:EPSG:4326">
       <gml:surfaceMember>
         <gml:Polygon>
           <gml:exterior>
             <gml:LinearRing>
               <gml:posList>
                 37.51099 -88.071564 37.476273 -88.087883 

WFS 1.0 output format GML32
```````````````````````````````

* GML3.2: 
  
  http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.0.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1&outputFormat=gml32

  The GML32 output uses ``http://www.opengis.net/gml/srs/epsg.xml#4326`` reference, with data in x/y order:
  
  .. code-block:: xml
  
     <gml:MultiSurface srsName="http://www.opengis.net/gml/srs/epsg.xml#4326" gml:id="states.1.the_geom">
       <gml:surfaceMember>
         <gml:Polygon gml:id="states.1.the_geom.1">
           <gml:exterior>
             <gml:LinearRing>
               <gml:posList>-88.071564 37.51099 -88.087883 37.476273 

* GML3.2 reproject to ``EPSG:4326``:
  
  http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.0.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1&outputFormat=gml32&srsName=EPSG:4326

  The GML32 output uses ``http://www.opengis.net/gml/srs/epsg.xml#4326`` reference, with data in x/y order:

  .. code-block:: xml
    
     <gml:MultiSurface srsName="http://www.opengis.net/gml/srs/epsg.xml#4326" gml:id="states.1.the_geom">
       <gml:surfaceMember>
         <gml:Polygon gml:id="states.1.the_geom.1">
           <gml:exterior>
             <gml:LinearRing>
               <gml:posList>
                 -88.071564 37.51099 -88.087883 37.476273
                 
* GML3.2 reproject to ``urn:x-ogc:def:crs:EPSG:4326``:
  
  http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.0.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1&outputFormat=gml32&srsName=urn:x-ogc:def:crs:EPSG:4326
  
  GML3.2 output using ``urn:x-ogc:def:crs:EPSG:4326`` reference and data in y/x order:

  .. code-block:: xml
    
     <gml:MultiSurface srsName="urn:ogc:def:crs:EPSG::4326" gml:id="states.1.the_geom">
       <gml:surfaceMember>
         <gml:Polygon gml:id="states.1.the_geom.1">
           <gml:exterior>
             <gml:LinearRing><gml:posList>
               37.51099 -88.071564 37.476273 -88.087883 

WFS 1.1 Axis Order
------------------

**GetCapabilities** describes ``topp:states`` using:

http://localhost:8080/geoserver/ows?service=wfs&version=1.1.0&request=GetCapabilities

.. code-block:: xml

   <FeatureType>
     <Name>topp:states</Name>
     <Title>USA Population</Title>
     <Abstract>This is some census data on the states.</Abstract>
     <ows:Keywords>
       <ows:Keyword>census</ows:Keyword><ows:Keyword>united</ows:Keyword><ows:Keyword>boundaries</ows:Keyword><ows:Keyword>state</ows:Keyword><ows:Keyword>states</ows:Keyword>
     </ows:Keywords>
     <DefaultSRS>urn:x-ogc:def:crs:EPSG:4326</DefaultSRS>
     <ows:WGS84BoundingBox>
       <ows:LowerCorner>-124.731422 24.955967</ows:LowerCorner>
       <ows:UpperCorner>-66.969849 49.371735</ows:UpperCorner>
     </ows:WGS84BoundingBox></FeatureType>    
  
WFS 1.1 describes the ``WGS84BoundingBox`` as a lower and upper corner in x/y order.

.. warning:: This combination is inconsistent with ``DefaultSRS`` definition and the ``LowerCorner`` and ``UpperCorner`` coordinate order and may confuse client applications.
   
   The result matches the WFS 1.1.0 Implementation Specification GetCapabilities examples.

WFS 1.1 *GetFeature* request defaults to GML3 output, and the default ``urn:x-ogc:def:crs:EPSG:4326`` spatial reference system used to publish the layer:

* WFS 1.1 Default:
  
  http://localhost:8080/geoserver/ows?service=WFS&version=1.1.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1

  The GML3.1 output uses ``urn:x-ogc:def:crs:EPSG:4326`` reference, with data in y/x order:

  .. code-block:: xml

     <gml:MultiSurface srsName="urn:x-ogc:def:crs:EPSG:4326">
       <gml:surfaceMember>
         <gml:Polygon>
           <gml:exterior>
             <gml:LinearRing>
               <gml:posList>
                  37.51099 -88.071564 37.476273 -88.087883  

* WFS 1.1 reproject to ``EPSG:4326``:
  
  http://localhost:8080/geoserver/ows?service=WFS&version=1.1.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1&srsName=EPSG:4326
  
  The GML3.1 output uses ``http://www.opengis.net/gml/srs/epsg.xml#4326`` reference, with data in x/y order:
  
  .. code-block:: xml
  
     <gml:MultiSurface srsName="http://www.opengis.net/gml/srs/epsg.xml#4326">
       <gml:surfaceMember>
         <gml:Polygon>
           <gml:exterior>
             <gml:LinearRing>
               <gml:posList>
                 -88.071564 37.51099 -88.087883 37.476273
  .. note:: The `srsName` and `posList` coordinate order are consistent.
  
     This approach can be used to force x/y order.

* WFS 1.1 reproject to ``urn:x-ogc:def:crs:EPSG:4326``:
  
  http://localhost:8080/geoserver/ows?service=WFS&version=1.1.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1&srsName=urn:x-ogc:def:crs:EPSG:4326
  
  The GML3.1 output uses ``http://www.opengis.net/gml/srs/epsg.xml#4326`` reference, with data in y/x order:
  
  .. code-block:: xml
  
     <gml:MultiSurface srsName="http://www.opengis.net/gml/srs/epsg.xml#4326">
       <gml:surfaceMember>
         <gml:Polygon>
           <gml:exterior>
             <gml:LinearRing>
               <gml:posList>
                 37.51099 -88.071564 37.476273 -88.087883

WFS 1.1 output format GML2
``````````````````````````

* GML2:
  
  
  http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.1.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1&outputFormat=gml2

  GML2 output uses ``http://www.opengis.net/gml/srs/epsg.xml#4326`` reference, with data in y/x order:

  .. code-block:: xml
  
     <gml:MultiPolygon srsName="http://www.opengis.net/gml/srs/epsg.xml#4326">
       <gml:polygonMember>
         <gml:Polygon><gml:outerBoundaryIs>
           <gml:LinearRing>
             <gml:coordinates decimal="." cs="," ts=" ">
               37.51099,-88.071564 37.476273,-88.087883

  
* GML2 reproject to ``EPSG:4326``:
  
  http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.1.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1&outputFormat=gml2&srsName=EPSG:4326

  GML2 output uses ``http://www.opengis.net/gml/srs/epsg.xml#4326`` reference, with data in x/y order:

  .. code-block:: xml
  
     <gml:MultiPolygon srsName="http://www.opengis.net/gml/srs/epsg.xml#4326">
       <gml:polygonMember>
         <gml:Polygon>
           <gml:outerBoundaryIs>
             <gml:LinearRing>
               <gml:coordinates decimal="." cs="," ts=" ">
                 -88.071564,37.51099 -88.087883,37.476273
  .. note:: The `srsName` and `posList` coordinate order are consistent.
  
     This approach can be used to force x/y order.

WFS 1.1 output format GML3
````````````````````````````

* GML3:


  http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.1.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1&outputFormat=gml3

  GML3.1 output uses ``http://www.opengis.net/gml/srs/epsg.xml#4326`` reference, with data in y/x order:
  
  .. code-block:: xml
  
     <gml:MultiSurface srsName="http://www.opengis.net/gml/srs/epsg.xml#4326">
       <gml:surfaceMember>
         <gml:Polygon>
           <gml:exterior>
             <gml:LinearRing>
               <gml:posList>
                 37.51099 -88.071564 37.476273 -88.087883

* GML3 reproject to ``EPSG:4326``:
  
  http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.1.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1&outputFormat=gml3&srsName=EPSG:4326
  
  GML3.1 output uses ``http://www.opengis.net/gml/srs/epsg.xml#4326`` reference, *but has changed the data to x/y order*:
  
  .. code-block:: xml
  
     <gml:MultiSurface srsName="http://www.opengis.net/gml/srs/epsg.xml#4326">
       <gml:surfaceMember>
         <gml:Polygon>
           <gml:exterior>
             <gml:LinearRing>
               <gml:posList>
                 -88.071564 37.51099 -88.087883 37.476273
  .. note:: The `srsName` and `posList` coordinate order are consistent.
     
     This approach can be used to force x/y order.
   
* GML3 reproject to ``urn:x-ogc:def:crs:EPSG:4326``
  
  http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.1.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1&outputFormat=gml3&srsName=urn:x-ogc:def:crs:EPSG:4326
  
  GML3.1 output using ``urn:x-ogc:def:crs:EPSG:4326`` reference and data in y/x order:
  
  .. code-block:: xml
  
     <gml:MultiSurface srsName="http://www.opengis.net/gml/srs/epsg.xml#4326">
       <gml:surfaceMember>
         <gml:Polygon>
           <gml:exterior>
             <gml:LinearRing>
               <gml:posList>
                 -88.071564 37.51099 -88.087883 37.476273
  .. note:: The `srsName` and `posList` coordinate order are consistent.
     
     This approach can be used to force x/y order.

WFS 1.1 output format GML32
````````````````````````````

* GML3.2:
  
  http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.1.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1&outputFormat=gml32

  The GML32 output uses ``http://www.opengis.net/gml/srs/epsg.xml#4326`` reference, with data in y/x order:
  
  .. code-block:: xml
  
     <gml:MultiSurface srsName="urn:ogc:def:crs:EPSG::4326" gml:id="states.1.the_geom">
       <gml:surfaceMember><gml:Polygon gml:id="states.1.the_geom.1">
         <gml:exterior>
           <gml:LinearRing>
             <gml:posList>37.51099 -88.071564 37.476273 -88.087883


* GML3.2 reproject to ``EPSG:4326``:
  
  http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.0.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1&outputFormat=gml32&srsName=EPSG:4326

  The GML32 output uses ``http://www.opengis.net/gml/srs/epsg.xml#4326`` reference, with data in x/y order:

  .. code-block:: xml
    
     <gml:MultiSurface srsName="http://www.opengis.net/gml/srs/epsg.xml#4326" gml:id="states.1.the_geom">
       <gml:surfaceMember>
         <gml:Polygon gml:id="states.1.the_geom.1">
           <gml:exterior>
             <gml:LinearRing>
               <gml:posList>-88.071564 37.51099 -88.087883 37.476273
               
* GML3.2 reproject to ``urn:x-ogc:def:crs:EPSG:4326``:
  
  http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.0.0&request=GetFeature&typeName=topp%3Astates&featureId=states.1&outputFormat=gml32&srsName=urn:x-ogc:def:crs:EPSG:4326
  
  GML3.2 output using ``urn:x-ogc:def:crs:EPSG:4326`` reference and data in y/x order:

  .. code-block:: xml
    
     <gml:MultiSurface srsName="urn:ogc:def:crs:EPSG::4326" gml:id="states.1.the_geom">
       <gml:surfaceMember>
         <gml:Polygon gml:id="states.1.the_geom.1">
           <gml:exterior>
             <gml:LinearRing><gml:posList>37.51099 -88.071564 37.476273 -88.087883 



WFS 2.0 Axis Order
------------------

**GetCapabilities** describes ``topp:states`` using:

http://localhost:8080/geoserver/ows?service=wfs&version=2.0.0&request=GetCapabilities

.. code-block:: xml

   <FeatureType>
     <Name>topp:states</Name>
     <Title>USA Population</Title>
     <Abstract>This is some census data on the states.</Abstract>
     <ows:Keywords>
       <ows:Keyword>census</ows:Keyword><ows:Keyword>united</ows:Keyword><ows:Keyword>boundaries</ows:Keyword><ows:Keyword>state</ows:Keyword><ows:Keyword>states</ows:Keyword>
     </ows:Keywords>
     <DefaultCRS>urn:ogc:def:crs:EPSG::4326</DefaultCRS>
     <ows:WGS84BoundingBox>
       <ows:LowerCorner>-124.731422 24.955967</ows:LowerCorner>
       <ows:UpperCorner>-66.969849 49.371735</ows:UpperCorner>
     </ows:WGS84BoundingBox>
   </FeatureType>
   
WFS 2.0 describes the ``WGS84BoundingBox`` as a lower and upper corner in x/y order.

.. warning:: This combination is inconsistent with ``DefaultSRS`` definition and the ``LowerCorner`` and ``UpperCorner`` coordinate order and may confuse client applications.
   
   The result matches the WFS 2.0 GetCapabilities examples.

WFS 2.0 *GetFeature* request defaults to GML3.2 output, and the default ``urn:ogc:def:crs:EPSG::4326`` spatial reference system used to publish the layer:

* WFS 2.0 Default:
  
  http://localhost:8080/geoserver/ows?service=WFS&version=2.0.0&request=GetFeature&typeNames=topp%3Astates&featureId=states.1

  The GML3.2 output uses ``urn:ogc:def:crs:EPSG::4326`` reference, with data in y/x order:

  .. code-block:: xml

     <gml:MultiSurface srsName="urn:ogc:def:crs:EPSG::4326" gml:id="states.1.the_geom">
       <gml:surfaceMember>
         <gml:Polygon gml:id="states.1.the_geom.1">
           <gml:exterior><gml:LinearRing>
             <gml:posList>
               37.51099 -88.071564 37.476273 -88.087883  

* WFS 2.0 reproject to ``EPSG:4326``:

  http://localhost:8080/geoserver/ows?service=WFS&version=2.0.0&request=GetFeature&typeNames=topp%3Astates&featureId=states.1&srsName=EPSG:4326

  The GML3.2 output uses ``http://www.opengis.net/gml/srs/epsg.xml#4326`` reference, with data in x/y order:

  .. code-block:: xml

     <gml:MultiSurface srsName="http://www.opengis.net/gml/srs/epsg.xml#4326" gml:id="states.1.the_geom">
       <gml:surfaceMember>
         <gml:Polygon gml:id="states.1.the_geom.1">
           <gml:exterior><gml:LinearRing>
             <gml:posList>
               -88.071564 37.51099 -88.087883 37.476273 

* WFS 2.0 reproject to ``urn:ogc:def:crs:EPSG::4326``
  http://localhost:8080/geoserver/ows?service=WFS&version=2.0.0&request=GetFeature&typeNames=topp%3Astates&featureId=states.1&srsName=urn:ogc:def:crs:EPSG::4326

  The GML3.2 output uses ``urn:ogc:def:crs:EPSG::4326`` reference, with data in y/x order:

  .. code-block:: xml

     <gml:MultiSurface srsName="urn:ogc:def:crs:EPSG::4326" gml:id="states.1.the_geom">
       <gml:surfaceMember>
         <gml:Polygon gml:id="states.1.the_geom.1">
           <gml:exterior><gml:LinearRing>
             <gml:posList>
               37.51099 -88.071564 37.476273 -88.087883 37.442852
                  
WFS 2.0 output format GML2
``````````````````````````

* GML2:
  
  http://localhost:8080/geoserver/ows?service=WFS&version=2.0.0&request=GetFeature&typeNames=topp%3Astates&featureId=states.1&outputFormat=gml2

  .. code-block:: xml
  
     <gml:MultiPolygon srsName="http://www.opengis.net/gml/srs/epsg.xml#4326">
       <gml:polygonMember>
         <gml:Polygon>
           <gml:outerBoundaryIs>
             <gml:LinearRing>
               <gml:coordinates decimal="." cs="," ts=" ">
                 37.51099,-88.071564 37.476273,-88.087883 

* GML2 reproject to ``EPSG:4326``:
  
  http://localhost:8080/geoserver/ows?service=WFS&version=2.0.0&request=GetFeature&typeNames=topp%3Astates&featureId=states.1&outputFormat=gml2&srsName=EPSG:4326

  .. code-block:: xml
  
     <gml:MultiPolygon srsName="http://www.opengis.net/gml/srs/epsg.xml#4326">
       <gml:polygonMember>
         <gml:Polygon>
           <gml:outerBoundaryIs>
             <gml:LinearRing>
               <gml:coordinates decimal="." cs="," ts=" ">
                 -88.071564,37.51099 -88.087883,37.476273
  .. note:: The `srsName` and `posList` coordinate order are consistent.
     
     This approach can be used to force x/y order.

* GML2 reproject to ``urn:x-ogc:def:crs:EPSG:4326``:
  
  http://localhost:8080/geoserver/ows?service=WFS&version=2.0.0&request=GetFeature&typeNames=topp%3Astates&featureId=states.1&outputFormat=gml2&srsName=urn:x-ogc:def:crs:EPSG:4326

  .. code-block:: xml
  
     <gml:MultiPolygon srsName="http://www.opengis.net/gml/srs/epsg.xml#4326">
       <gml:polygonMember>
         <gml:Polygon>
           <gml:outerBoundaryIs>
             <gml:LinearRing>
               <gml:coordinates decimal="." cs="," ts=" ">
                 37.51099,-88.071564 37.476273,-88.087883

WFS 2.0 output format GML3
``````````````````````````

* GML3:
  
  http://localhost:8080/geoserver/ows?service=WFS&version=2.0.0&request=GetFeature&typeNames=topp%3Astates&featureId=states.1&outputFormat=gml3
  
  .. code-block:: xml
  
     <gml:MultiSurface srsName="urn:x-ogc:def:crs:EPSG:4326">
       <gml:surfaceMember>
         <gml:Polygon>
           <gml:exterior>
             <gml:LinearRing>
               <gml:posList>
                 37.51099 -88.071564 37.476273 -88.087883 
                 
* GML3 reproject to ``EPSG:4326``:
  
  http://localhost:8080/geoserver/ows?service=WFS&version=2.0.0&request=GetFeature&typeNames=topp%3Astates&featureId=states.1&outputFormat=gml3&srsName=EPSG:4326
  
  .. code-block:: xml
  
     <gml:MultiSurface srsName="urn:x-ogc:def:crs:EPSG:4326">
       <gml:surfaceMember>
         <gml:Polygon>
           <gml:exterior>
             <gml:LinearRing>
               <gml:posList>
                 -88.071564 37.51099 -88.087883 37.476273

  .. warning:: This combination is inconsistent between `srsName` and `posList` coordinate order and may confuse applications expecting a valid GML3 document.
  
     This approach can be used to force x/y order.
      
* GML3 reproject to ``urn:x-ogc:def:crs:EPSG:4326``:
  
  http://localhost:8080/geoserver/ows?service=WFS&version=2.0.0&request=GetFeature&typeNames=topp%3Astates&featureId=states.1&outputFormat=gml3&srsName=urn:x-ogc:def:crs:EPSG:4326
  
  .. code-block:: xml
  
     <gml:MultiSurface srsName="urn:x-ogc:def:crs:EPSG:4326">
       <gml:surfaceMember>
         <gml:Polygon>
           <gml:exterior>
             <gml:LinearRing>
               <gml:posList>
                 37.51099 -88.071564 37.476273 -88.087883
   
WFS 2.0 output format GML32
```````````````````````````

* GML32:
  
  http://localhost:8080/geoserver/ows?service=WFS&version=2.0.0&request=GetFeature&typeNames=topp%3Astates&featureId=states.1&outputFormat=gml32

  .. code-block:: xml
  
     <gml:MultiSurface srsName="urn:ogc:def:crs:EPSG::4326" gml:id="states.1.the_geom">
       <gml:surfaceMember>
         <gml:Polygon gml:id="states.1.the_geom.1"><gml:exterior>
           <gml:LinearRing>
             <gml:posList>
               37.51099 -88.071564 37.476273 -88.087883 

* GML32 reproject to ``EPSG:4326``:
  
  http://localhost:8080/geoserver/ows?service=WFS&version=2.0.0&request=GetFeature&typeNames=topp%3Astates&featureId=states.1&outputFormat=gml32&srsName=EPSG:4326

  .. code-block:: xml
  
     <gml:MultiSurface srsName="urn:ogc:def:crs:EPSG::4326" gml:id="states.1.the_geom">
       <gml:surfaceMember>
         <gml:Polygon gml:id="states.1.the_geom.1"><gml:exterior>
           <gml:LinearRing>
             <gml:posList>
               -88.071564 37.51099 -88.087883 37.476273
               
  .. warning:: This combination is inconsistent between `srsName` and `posList` coordinate order and may confuse applications expecting a valid GML3 document.
   
     This approach can be used to force x/y order.
      
* GML32 reproject to ``urn:x-ogc:def:crs:EPSG:4326``:
  
  http://localhost:8080/geoserver/ows?service=WFS&version=2.0.0&request=GetFeature&typeNames=topp%3Astates&featureId=states.1&outputFormat=gml32&srsName=urn:x-ogc:def:crs:EPSG:4326

  .. code-block:: xml
  
     <gml:MultiSurface srsName="urn:ogc:def:crs:EPSG::4326" gml:id="states.1.the_geom">
       <gml:surfaceMember>
         <gml:Polygon gml:id="states.1.the_geom.1"><gml:exterior>
           <gml:LinearRing>
             <gml:posList>
               37.51099 -88.071564 37.476273 -88.087883