mapnik/tests/visual_tests/styles/text-allow-overlap-expr.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE Map>
<Map background-color="white" srs="+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs">
  <Parameters>
    <Parameter name="sizes">500, 500</Parameter>
  </Parameters>
  <FontSet name="book">
    <Font face-name="DejaVu Sans Book"/>
  </FontSet>

  <Layer name="layer" srs="+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs">
    <StyleName>My Style</StyleName>
    <Datasource>
      <Parameter name="type">csv</Parameter>
      <Parameter name="extent">-0.5, -0.5, 0.5, 0.5</Parameter>
<Parameter name="inline">
lat,long,test,text
 0.25,-0.35,noexpr-true,ABC
 0.25,-0.35,noexpr-true,XYZ
 0.25,-0.12,noexpr-false,ABC
 0.25,-0.12,noexpr-false,XYZ
 0.25, 0.11,noexpr-true,ABC
 0.25, 0.11,noexpr-false,XYZ
 0.25, 0.35,noexpr-false,ABC
 0.25, 0.35,noexpr-true,XYZ
 0   ,-0.35,true,ABC
 0   ,-0.35,true,XYZ
 0   ,-0.12,false,ABC
 0   ,-0.12,false,XYZ
 0   , 0.11,true,ABC
 0   , 0.11,false,XYZ
 0   , 0.35,false,ABC
 0   , 0.35,true,XYZ
      </Parameter>
    </Datasource>
  </Layer>

    <Style name="My Style" filter-mode="first">
    <Rule>
      <Filter>[test] = "noexpr-true"</Filter>
      <TextSymbolizer fontset-name="book" size="16" placement="point" dx="0" dy="0" allow-overlap="true">[text]</TextSymbolizer>
    </Rule>
    <Rule>
      <Filter>[test] = "noexpr-false"</Filter>
      <TextSymbolizer fontset-name="book" size="16" placement="point" dx="0" dy="0" allow-overlap="false">[text]</TextSymbolizer>
    </Rule>
    <Rule>
      <TextSymbolizer fontset-name="book" size="16" placement="point" dx="0" dy="0" allow-overlap="[test]">[text]</TextSymbolizer>
    </Rule>
  </Style>

</Map>