$webwork.htmlEncode($page.space.name) : InlineFeature

Geoserver experimentally supports a SLD 1.1 concept - inline features. This basically allows you to include a mini-dataset in your SLD request.
<?xml version="1.0" encoding="UTF-8"?>

<ogc:GetMap xmlns:ogc="http://www.opengis.net/ows" 
            xmlns:gml="http://www.opengis.net/gml" 
            version="1.2.0"
            service="WMS">

  <StyledLayerDescriptor version="1.0.0" 
                         xsi:schemaLocation="http://www.opengis.net/sld StyledLayerDescriptor.xsd"
                         xmlns="http://www.opengis.net/sld" 
                         xmlns:ogc="http://www.opengis.net/ogc" 
                         xmlns:xlink="http://www.w3.org/1999/xlink"
                         xmlns:dave="http://blasby.com" 
                         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <UserLayer>
      <Name>Inline</Name>

      <InlineFeature>
        <FeatureCollection>

          <featureMember>
            <BodyPart>
              <Type>Face</Type>
              <polygonProperty>
                <gml:Polygon>
                  <gml:outerBoundaryIs>
                    <gml:LinearRing>
                      <gml:coordinates>
                        496,273 492,241 481,211 462,184 437,161 407,141 373,126 335,117 296,114 257,116 219,125 185,139
                        155,159 130,184 111,212 100,243 96,274 100,306 111,336 130,364 155,388 185,408 219,422 257,431
                        296,434 335,430 373,420 407,405 437,385 462,362 481,335 492,305 496,273
                      </gml:coordinates>
                    </gml:LinearRing>
                  </gml:outerBoundaryIs>
                </gml:Polygon>
              </polygonProperty>
            </BodyPart>
          </featureMember>

          <featureMember>
            <BodyPart>
              <Type>Eye</Type>
              <polygonProperty>
                <gml:Polygon>
                  <gml:outerBoundaryIs>
                    <gml:LinearRing>
                      <gml:coordinates>
                        259,346 258,341 256,336 252,332 247,329 241,326 234,324 227,323 219,323 211,323 204,324 197,326
                        191,328 186,332 182,336 180,340 179,345 180,350 182,354 186,358 191,362 197,364 204,366 211,367
                        219,368 227,368 234,367 241,365 247,362 252,359 256,355 258,350 259,346
                      </gml:coordinates>
                    </gml:LinearRing>
                  </gml:outerBoundaryIs>
                </gml:Polygon>
              </polygonProperty>
            </BodyPart>
          </featureMember>

          <featureMember>
            <BodyPart>
              <Type>Eye</Type>
              <polygonProperty>
                <gml:Polygon>
                  <gml:outerBoundaryIs>
                    <gml:LinearRing>
                      <gml:coordinates>
                        406,346 405,341 403,336 399,332 394,329 388,326 381,324 374,323 366,323 358,323 351,324 344,326
                        338,328 333,332 329,336 327,340 326,345 327,350 329,354 333,358 338,362 344,364 351,366 358,367
                        366,368 374,368 381,367 388,365 394,362 399,359 403,355 405,350 406,346
                      </gml:coordinates>
                    </gml:LinearRing>
                  </gml:outerBoundaryIs>
                </gml:Polygon>
              </polygonProperty>
            </BodyPart>
          </featureMember>

          <featureMember>
            <BodyPart>
              <Type>Nose</Type>
              <polygonProperty>
                <gml:Polygon>
                  <gml:outerBoundaryIs>
                    <gml:LinearRing>
                      <gml:coordinates>
                        310,286 310,282 308,278 307,275 304,272 301,269 298,268 294,266 290,266 286,266 282,268 279,269
                        276,272 273,275 272,278 270,282 270,286 270,290 272,294 273,297 276,300 279,303 282,304 286,306
                        290,306 294,306 298,304 301,303 304,300 307,297 308,294 310,290 310,286
                      </gml:coordinates>
                    </gml:LinearRing>
                  </gml:outerBoundaryIs>
                </gml:Polygon>
              </polygonProperty>
            </BodyPart>
          </featureMember>

          <featureMember>
            <BodyPart>
              <Type>Mouth</Type>
              <polygonProperty>
                <gml:Polygon>
                  <gml:outerBoundaryIs>
                    <gml:LinearRing>
                      <gml:coordinates>
                        397,226 396,209 396,196 390,185 384,175 368,163 353,155 331,150 308,149 283,148 261,153 231,163
                        209,175 195,189 186,209 182,221 187,226 193,214 195,205 200,197 203,192 215,185 226,177 241,171
                        256,167 266,163 281,161 297,161 321,160 341,160 359,168 371,175 382,185 388,197 390,215 390,225
                        394,226 397,226
                      </gml:coordinates>
                    </gml:LinearRing>
                  </gml:outerBoundaryIs>
                </gml:Polygon>
              </polygonProperty>
            </BodyPart>
          </featureMember>

        </FeatureCollection>
      </InlineFeature>

      <UserStyle>
        <FeatureTypeStyle>
          <Rule>

            <Filter>
              <PropertyIsEqualTo>
                <PropertyName>Type</PropertyName>
                <Literal>Face</Literal>
              </PropertyIsEqualTo>
            </Filter>
            <PolygonSymbolizer>
              <Fill>
                <CssParameter name="fill">
                  <ogc:Literal>#FFF265</ogc:Literal>
                </CssParameter>
                <CssParameter name="fill-opacity">
                  <ogc:Literal>1.0</ogc:Literal>
                </CssParameter>
              </Fill>
              <Stroke>
                <CssParameter name="stroke">
                  <ogc:Literal>#222222</ogc:Literal>
                </CssParameter>
              </Stroke>
            </PolygonSymbolizer>
          </Rule>
        </FeatureTypeStyle>
        <FeatureTypeStyle>
          <Rule>
            <Filter>
              <Or>
                <PropertyIsEqualTo>
                  <PropertyName>Type</PropertyName>
                  <Literal>Nose</Literal>
                </PropertyIsEqualTo>
                <PropertyIsEqualTo>
                  <PropertyName>Type</PropertyName>
                  <Literal>Mouth</Literal>
                </PropertyIsEqualTo>
              </Or>
            </Filter>
            <PolygonSymbolizer>
              <Fill>
                <CssParameter name="fill">
                  <ogc:Literal>#F00620</ogc:Literal>
                </CssParameter>
                <CssParameter name="fill-opacity">
                  <ogc:Literal>1.0</ogc:Literal>
                </CssParameter>
              </Fill>
              <Stroke>
                <CssParameter name="stroke">
                  <ogc:Literal>#FF0000</ogc:Literal>
                </CssParameter>
              </Stroke>
            </PolygonSymbolizer>
          </Rule>
        </FeatureTypeStyle>
        <FeatureTypeStyle>
          <Rule>
            <Filter>
              <Or>
                <PropertyIsEqualTo>
                  <PropertyName>Type</PropertyName>
                  <Literal>Eye</Literal>
                </PropertyIsEqualTo>
              </Or>
            </Filter>
            <PolygonSymbolizer>
              <Fill>
                <CssParameter name="fill">
                  <ogc:Literal>#DD06E0</ogc:Literal>
                </CssParameter>
                <CssParameter name="fill-opacity">
                  <ogc:Literal>1.0</ogc:Literal>
                </CssParameter>
              </Fill>
              <Stroke>
                <CssParameter name="stroke">
                  <ogc:Literal>#FF00FF</ogc:Literal>
                </CssParameter>
              </Stroke>
            </PolygonSymbolizer>
          </Rule>
        </FeatureTypeStyle>

      </UserStyle>

    </UserLayer>

  </StyledLayerDescriptor>

  <BoundingBox>
    <gml:coord>
      <gml:X>0</gml:X>
      <gml:Y>0</gml:Y>
    </gml:coord>
    <gml:coord>
      <gml:X>500</gml:X>
      <gml:Y>500</gml:Y>
    </gml:coord>
  </BoundingBox>

  <Output>
    <Format>image/jpeg</Format>
    <Transparent>false</Transparent>
    <Size>
      <Width>501</Width>
      <Height>501</Height>
    </Size>
  </Output>

  <Exceptions>application/vnd.ogc.se+xml</Exceptions>

</ogc:GetMap>