The <theme_modifiers> element has the following definition:

<!ELEMENT theme_modifiers (theme_decorations)? >

The theme modifiers enable you to override the theme definition on a base map, without having to edit and change the base map definition. The <theme_decorations> element has the same attributes as the <theme> element (described in theme Element).

The following example overrides the labels_always_on attribute for the theme_us_airport theme on the base map FORCED_LABELING.

<?xml version="1.0" standalone="yes"?>
<map_request title="Override labeling on map definition"
             basemap="FORCED_LABELING"
             datasource="tilsmenv"
             width="500"
             height="375"
             bgcolor="#a6caf0"
             antialiase="true"
             format="PNG_URL">
    <center size="15.0">
        <geoFeature>
            <geometricProperty typeName="center">
                <Point>
                    <coordinates>-122.4,37.8</coordinates>
                </Point>
            </geometricProperty>
        </geoFeature>
    </center>
    <theme_modifiers>
        <theme_decorations name="theme_us_airport"
                           label_always_on="false" />
    </theme_modifiers>
</map_request>