[Zope] LDAPUserFolder Question

Hi, I have LDAPUserFolder 2.6 on Zope 2.9.5-Final. Everything is working as expected, but there is one thing I'm not clear on. I've added uid as User ID to the LDAP Schema, and am using it as the Login Name Attribute. The authentication works flawlessly. Under User ID Attribute I have Canonical Name (cn). That should be returning the full name of the user. However when I use something like: <dtml-call expr="REQUEST.set( 'User_Name',REQUEST.AUTHENTICATED_USER.getUserName())"> I get the uid and not the cn. Any idea how I can get the cn? Thanks, Sean