Specifies the claim type so the WS-Federation service can recognize the type of token that is exchanged between federation partners.
The EmailAddress claim type is used to identify a specific security principal by an email address.
The UPN claim type is used to identify a specific security principal via a User Principal Name.
The CommonName claim type is used to identify a security principal via a CN value consistent with X.500 naming conventions. The value of this claim is not necessarily unique and should not be used for authorization purposes.