<xs:documentation>Service token, identifying the service generating the original request.</xs:documentation>
<xs:documentation>Service tokens, separated by spaces if they are more than one, identifying the service generating the original request.</xs:documentation>
<xs:documentation>Device token, identifying the device generating the original request.</xs:documentation>
<xs:documentation>Device tokens, separated by spaces if they are more than one, identifying the device generating the original request.</xs:documentation>