<attribute name="show">
    <annotation>
        <documentation>
        The 'show' attribute is used to communicate the desired presentation 
        of the ending resource on traversal from the starting resource; it's 
        value should be treated as follows: 
        new - load ending resource in a new window, frame, pane, or other 
              presentation context
        replace - load the resource in the same window, frame, pane, or 
                  other presentation context
        embed - load ending resource in place of the presentation of the 
                starting resource
        other - behavior is unconstrained; examine other markup in the 
                link for hints 
        none - behavior is unconstrained 
      </documentation>
    </annotation>
    <simpleType>
        <restriction base="string">
            <enumeration value="new" />
            <enumeration value="replace" />
            <enumeration value="embed" />
            <enumeration value="other" />
            <enumeration value="none" />
        </restriction>
    </simpleType>
</attribute>