Integration Broker providing WebServices - Fault Processing

Is there any references out there providing examples of returning functional Faults from a PS provided WebService?

For example:

A service to search for Vendor duplicates by ID numbers.  Required inputs are STD_ID_NUM_QUAL and STD_ID_NUM.

If a requester fails to provide a STD_ID_NUM_QUAL, return appropriate Fault;

If a requester fails to provide a STD_ID_NUM, return appropriate Fault;

If a requester provides an invalid STD_ID_NUM_QUAL type, return appropriate Fault;