LDAP connectivity

If I connect with "Toto + password" and toto + same password => I have 2 ressource in Projectoria ?

YES
=> But this is an issue, registered as #532 and fixed for V2.0.0
Registration in Project'Or RIA in not case sensitive. So you should not create a new user when you enter your logging LDAP account with or without uppercases.
Most of ldap (I don't know if it's an ldap rule) don't care about case in user names, so this should be correct now.

Can be used: CN = PrincipalName? (Today only CN = UserName)

The syntax is whateven you whant to identify you ldap user.
Defaut search is 'uid=%USERNAME%" , but it should also be 'dn=%USERNAME%, where %USERNAME% is the Project'Or RIA name of the user. Only this %USERNAME% can be user as it is the login account in Project'Or RIA. On first connection, user is created with name=login account, resource name = 'cn' from Ldap.