• (Optional) If your LDAP server uses a custom POSIX LDAP scheme, you might need to set which LDAP attributes store the username, or the attributes that set group memberships. For example, if your LDAP scheme does not use the uid attribute to store the usernames, set the Username (userid) attribute name option. You can customize group-membership attributes using the POSIX group membership attribute name and GroupOfUniqueNames membership attribute name options.