[Geoserver-users] SLD: anchor point of a symbol?

Hi,

is there a way to set the achor point of a point symbol (graphic)? I only figured out how to set the anchor point of a label inside a symbol, but not for the whole symbol istself - I need to insert a symbol at its central bottom point.
I tried this, but it would not work:

<sld:Rule>
   <sld:Name>VKZ</sld:Name>
   <sld:Title>VKZ</sld:Title>
   <ogc:Filter>
     <ogc:PropertyIsEqualTo>
     <ogc:PropertyName>type</ogc:PropertyName>
     <ogc:Literal>vkz</ogc:Literal>
     </ogc:PropertyIsEqualTo>
   </ogc:Filter>
   <sld:PointSymbolizer>
     <sld:Graphic>
       <sld:ExternalGraphic>
         <sld:OnlineResource xlink:href="images/symbols/vkz.png"/>
         <sld:Format>image/png</sld:Format>
       </sld:ExternalGraphic>
       <sld:Size>9</sld:Size>
       <sld:Rotation>${angle}</sld:Rotation>
     </sld:Graphic>
     <sld:PointPlacement>
       <sld:AnchorPoint>
         <sld:AnchorPointX>0.5</sld:AnchorPointX>
         <sld:AnchorPointY>0.0</sld:AnchorPointY>
       </sld:AnchorPoint>
     </sld:PointPlacement>
   </sld:PointSymbolizer>
</sld:Rule>

Thanks for your help!
Uschi