libopc/test_docs/mce-test-2.xml

<Circles xmlns="http://schemas.openxmlformats.org/Circles/v1"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:v2="http://schemas.openxmlformats.org/Circles/v2"
         xmlns:v3="http://schemas.openxmlformats.org/Circles/v3">
    <mc:AlternateContent mc:Ignorable="v3">
        <mc:Choice Requires="v3">
            <v3:Circle Center="0,0" Radius="20" Color="Blue" Opacity="0.5" Luminance="13" />
            <v3:Circle Center="25,0" Radius="20" Color="Black" Opacity="0.5" Luminance="13" />
            <v3:Circle Center="50,0" Radius="20" Color="Red" Opacity="0.5" Luminance="13" />
            <v3:Circle Center="13,0" Radius="20" Color="Yellow" Opacity="0.5" Luminance="13" />
            <v3:Circle Center="38,0" Radius="20" Color="Green" Opacity="0.5" Luminance="13" />
        </mc:Choice>
        <mc:Fallback>
            <LuminanceFilter Luminance="13" mc:Ignorable="v2">
                <Circle Center="0,0" Radius="20" Color="Blue" v2:Opacity="0.5" />
                <Circle Center="25,0" Radius="20" Color="Black" v2:Opacity="0.5" />
                <Circle Center="50,0" Radius="20" Color="Red" v2:Opacity="0.5" />
                <Circle Center="13,0" Radius="20" Color="Yellow" v2:Opacity="0.5" />
                <Circle Center="38,0" Radius="20" Color="Green" v2:Opacity="0.5" />
            </LuminanceFilter>
        </mc:Fallback>
    </mc:AlternateContent>
</Circles>