Use the INSTANCEOF operator

Use the INSTANCEOF operator in a reference qualifier to shorten or simplify a complex class qualifier.

For example, you can use the INSTANCEOF operator for a reference field to the cmdb_ci table to specify that you want all subclasses of a class included in the results. The following reference qualifier returns all servers, including Linux, UNIX, Windows, and so on, because each of those subclasses extend the cmdb_ci_server class:
sys_class_nameINSTANCEOFcmdb_ci_server
Likewise, the following reference qualifier can be similarly simplified:
 u_active=true^sys_class_name=cmdb_ci_acc
^ORsys_class_name=cmdb_ci_computer
^ORsys_class_name=cmdb_ci_server
^ORsys_class_name=cmdb_ci_win_server
^ORsys_class_name=cmdb_ci_unix_server
^ORsys_class_name=cmdb_ci_linux_server
^ORsys_class_name=cmdb_ci_appl
^ORsys_class_name=cmdb_ci_netgear
If you use the INSTANCEOF operator, the reference qualifier is as follows:
 u_active=true^sys_class_name=cmdb_ci_acc
^ORsys_class_nameINSTANCEOFcmdb_ci_computer
^ORsys_class_name=cmdb_ci_appl
^ORsys_class_name=cmdb_ci_netgear

Troubleshooting

If you receive a Bad Gateway Error in Internet Explorer when searching in a reference lookup window, then you cannot use ref_qual_elements=* in the advanced reference qualifier.