A request XML packet retrieving descriptor of permissions includes the get-permission-descriptor operation node:
<packet version="1.6.3.0">
<role>
<get-permission-descriptor>
...
</get-permission-descriptor>
</role>
</packet>
This operation retrieves a permissions descriptor for a particular Panel user. The get-permission-descriptor node (site.xsd) has the following graphical representation:

It specifies a filtering rule. Data type: RoleSelectionPermissionFilter (site.xsd).
It specifies a role owner GUID. Data type: string.