mapnik/tests/data/good_maps/text_halo_and_collision.xml

<Map srs="+init=epsg:4326" background-color="steelblue">
<!-- test case for https://github.com/mapnik/mapnik/issues/1354 -->

    <Style name="labels">
        <Rule>
            <TextSymbolizer 
              face-name="DejaVu Sans Book"
              size="22"
              halo-radius="10"
              placement="point"
              allow-overlap="false">
                'this text halos should not overlap vertically'
              </TextSymbolizer>
        </Rule>
    </Style>


    <Layer name="points" srs="+init=epsg:4326">
        <StyleName>labels</StyleName>
        <Datasource>
            <Parameter name="type">csv</Parameter>
            <Parameter name="inline">
x,y
2,2
2,2.3
            </Parameter>
        </Datasource>
    </Layer>

    <!-- points to frame data view -->

    <Style name="frame">
        <Rule>
            <PointSymbolizer />
        </Rule>
    </Style>

    <Layer name="frame" srs="+init=epsg:4326">
        <StyleName>frame</StyleName>
        <Datasource>
            <Parameter name="type">csv</Parameter>
            <Parameter name="inline">
x,y
0,0
5,0
0,5
5,5
            </Parameter>
        </Datasource>
    </Layer>
    
</Map>