On the Identity Mapping screen, indicate to the nature of the subject identifier by selecting one the three Name ID types for WS-Federation. Your selection may affect the way that the SP looks up and associates your users to their local accounts.
Note that the Identity Mapping screen is not applicable to connections using the WS-Federation protocol in conjunction with JWT-based SSO tokens. Instead, work with the SP to define an attribute contract that it can use to map users to accounts at the SP site.
Select the type of name identifier that you and your SP have agreed to
Option Description Email Address This attribute is commonly used as a unique identifier for SSO and SLO. Make this selection, for example, if a user logs in using an email address or if the information is available for lookup in a local datastore. User Principal Name The username or other unique ID of the subject initiating the transaction. Make this selection, for example, if a username will be available from the current user session as part of a cookie or can be derived from a local datastore. Common Name This selection provides for anonymous SSO to your SP, generally using a hard-coded generalized logon. Make this selection if your partner agreement involves a many-to-one use case; for instance, if the SP has a group account set up for all users in a particular domain.