Can single SLD contain styles for different layer shapes?

Question

I'm interested in creating a single SLD that could be used for a layer group in GeoServer that contains layers in point, line and polygon shapes.

According to the documentation it says:

"GeoServer supports the use of a StyledLayerDescriptor document containing a single < NamedLayer > element, which contains a single < UserStyle > element to specify the styling."

and then:

"A Style Layer Descriptor is a StyledLayerDescriptor document containing any number of < NamedLayer > and elements, each of which may contain any number of < UserStyle > or < NamedStyle > elements."

This seems to imply that I could use a single SLD for all my layers. I have created a SLD with multiple < NamedLayer >. However, only the first is being interpreted by GeoServer:

<?xml version="1.0" encoding="ISO-8859-1"?>
<StyledLayerDescriptor version="1.0.0"
  xsi:schemaLocation="http://www.opengis.net/sld http://schemas.opengis.net/sld/1.0.0/StyledLayerDescriptor.xsd"
  xmlns="http://www.opengis.net/sld" xmlns:ogc="http://www.opengis.net/ogc"
  xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

  <NamedLayer>
    <Name>SAMPLE_EP_1</Name>
    <UserStyle>
      <Title>SAMPLE_EP_1</Title>
      <FeatureTypeStyle>
        <Rule>
          <Title>SAMPLE_EP_1</Title>
          <PointSymbolizer>
            <Graphic>
              <Mark>
                <WellKnownName>circle</WellKnownName>
                <Fill>
                  <CssParameter name="fill">#5D8A82</CssParameter>
                </Fill>
             <Stroke>
               <CssParameter name="stroke">#000000</CssParameter>
               <CssParameter name="stroke-width">1</CssParameter>
             </Stroke>
              </Mark>
              <Size>6</Size>
            </Graphic>
          </PointSymbolizer>
        </Rule>

      </FeatureTypeStyle>
    </UserStyle>
  </NamedLayer>


  <NamedLayer>
    <Name>SAMPLE_EP_2</Name>
    <UserStyle>
      <Title>SAMPLE_EP_2</Title>
      <FeatureTypeStyle>
        <Rule>
          <Title>SAMPLE_EP_2</Title>
          <LineSymbolizer>
            <Stroke>
              <CssParameter name="stroke">#5D8A82</CssParameter>
            </Stroke>
          </LineSymbolizer>
        </Rule>

      </FeatureTypeStyle>
    </UserStyle>
  </NamedLayer>



  <NamedLayer>
    <Name>SAMPLE_EP_3</Name>
    <UserStyle>
      <Title>SAMPLE_EP_3</Title>
      <FeatureTypeStyle>
        <Rule>
          <Title>SAMPLE_EP_3</Title>
          <PolygonSymbolizer>
            <Fill>
              <CssParameter name="fill">#FFFFFF</CssParameter>
              <CssParameter name="fill-opacity">1.0</CssParameter>
            </Fill>
            <Stroke>
              <CssParameter name="stroke">#FF69B4</CssParameter>
              <CssParameter name="stroke-width">1.0</CssParameter>
            </Stroke>
          </PolygonSymbolizer>

        </Rule>

      </FeatureTypeStyle>
    </UserStyle>
  </NamedLayer>
  
  
    <NamedLayer>
    <Name>SAMPLE_EP_4</Name>
    <UserStyle>
      <Title>SAMPLE_EP_4</Title>
      <FeatureTypeStyle>
        <Rule>
          <Title>SAMPLE_EP_4</Title>
          <PolygonSymbolizer>
            <Fill>
              <CssParameter name="fill">#BFFFCD
              </CssParameter>
            </Fill>
            <Stroke>
              <CssParameter name="stroke">#BFFFCD</CssParameter>
              <CssParameter name="stroke-width">1.0</CssParameter>
            </Stroke>
          </PolygonSymbolizer>
        </Rule>
      </FeatureTypeStyle>
    </UserStyle>
  </NamedLayer>
  
</StyledLayerDescriptor>

Answer 1

That is possible, look into the GeoServer documentation for "style groups", for example, in these pages:

• https://docs.geoserver.org/latest/en/user/styling/sld/working.html#style-layer-descriptor-styles
• https://docs.geoserver.org/latest/en/user/data/webadmin/layergroups.html#data-webadmin-layergroups