<group name="playerMetadataSpecific">
    <choice>
        <element ref="sportsml:player-metadata-american-football" />
        <element ref="sportsml:player-metadata-baseball" />
        <element ref="sportsml:player-metadata-basketball" />
        <element ref="sportsml:player-metadata-golf" />
        <element ref="sportsml:player-metadata-ice-hockey" />
        <element ref="sportsml:player-metadata-soccer" />
        <element ref="sportsml:player-metadata-tennis" />
        <element ref="sportsml:player-metadata-motor-racing" />
        <element ref="sportsml:player-metadata-curling" />
    </choice>
</group>