Applies to: Exchange Online | Exchange Server 2007 | Exchange Server 2010 | Exchange Server 2013 | Office 365
The UserSid element represents the security descriptor definition language (SDDL) form of the user security identifier in a serialized security context SOAP header. Token serialization is not supported.
The schema that describes this element is located in the EWS virtual directory of the computer that is running MicrosoftExchange Server 2007 that has the Client Access server role installed.