A user type configuration in which the `nsroledn` attribute value for static field values includes a configured value, such as `cn=admin-user,%(base_dn)s`, should still allow additional values to be specified, such as `cn=kolab-user,$root_dn` or `cn=imap-user,$root_dn`.
This can be achieved by examining the `auto_form_fields` for the same attribute key and by specifying `optional => true`.
Below is a snippet for user type configuration
```
$attributes = Array(
'auto_form_fields' => Array(
'nsroledn' => Array(
'optional' => true,
'type' => list
),
(...)
),
'form_fields' => Array(
(...)
),
'fields' => Array(
(...)
'nsroledn' => Array(
'cn=admin-user,%(base_dn)s'
)
)
);
```