Hello, I'm delegating the Authentication of my Sharepoint site to a Single Sign On solution named OpenAM. It works well. The mapping fonction is used to create 3 areas, the first is the intranet, the second is the extranet for the company's users with reduced rights, and the last is another extranet for our customers with reduced rights. The two first areas are using the same Active Directory / LDAP to identify the authenticated users, but there provider can not have the same name (I can not give the same name else sharepoint have an error). Is there a way to merge users recognised by different providers (in my case the first are named ldapmembership1:username and the second are named ldapmembership2:username) ? I don't know if I am very clear, if you want more explanation do not hesitate to ask. Thanks in advance for your help, Arnaud.