Errors -650 and -651 when expanding the schema through Yast Schema tool

The following errors are reported in dstrace when extending the schema with the Novell eDirectory Schema Extension Utility in Yast:
Error: Client create class <dhcpService> failed, ambiguous containment (-650)
Error: Client create class <dhcpService> failed, ambiguous naming (-651)

The ambiguous containment error is only reported for this class. The ambiguous naming  error is reported for a few other classes as well. To display the errors in dstrace, the Schema tag needs to be selected.

The errors are reported only when performing the schema extensions related to the Novell DHCP Services component. If this component is not selected, the error is not reported. If  this component is selected, the schema extension  will report the error for some of the classes but will eventually succeed to create the necessary classes. This error can be considered more like a warning than a real error for this reason.

The schema extensions for the DHCP components don't have an explicit definition for naming and containment components in some of its classes in the LDIF file that defines them. The naming and containment definitions are inherited from Top, its superclass, that's why the classes can be created successfully, regardless the warnings.