The org=realmName parameter allows a user to authenticate as a user in the specified realm.
A user who is not already a member of the specified realm will receive an error message when they attempt to authenticate with the realm parameter. A user profile, though, can be dynamically created in the Directory Server if all of the following are TRUE:
The User Profile attribute in the Core Authentication Service must be set to Dynamic or Dynamic with User Alias.
The user must successfully authenticate to the required module.
The user does not already have a profile in Directory Server.
From this parameter, the correct login page (based on the realm and its locale setting) will be displayed. If this parameter is not set, the default is the top-level realm. For example, an org URL might be: