<simpleType name="position.AmericanFootball.Vocabulary">
    <annotation>
        <documentation>.american-football</documentation>
    </annotation>
    <restriction base="string">
        <enumeration value="center" />
        <enumeration value="guard" />
        <enumeration value="end" />
        <enumeration value="tackle" />
        <enumeration value="running-back" />
        <enumeration value="half-back" />
        <enumeration value="full-back" />
        <enumeration value="quarterback" />
        <enumeration value="wide-receiver" />
        <enumeration value="receiver" />
        <enumeration value="lineman" />
        <enumeration value="safety" />
        <enumeration value="cornerback" />
        <enumeration value="linebacker" />
        <enumeration value="referee" />
        <enumeration value="linesman" />
        <enumeration value="line-judge" />
        <enumeration value="back-judge" />
        <enumeration value="side-judge" />
        <enumeration value="field-judge" />
        <enumeration value="coach" />
        <enumeration value="assistant-coach" />
    </restriction>
</simpleType>