The document provides step-by-step instructions for creating a custom fault in an Oracle SOA BPEL process. When student marks are input that are less than 0 or greater than 100, a custom "InvalidStudentMarksFault" fault will be thrown. The process defines the fault message in the WSDL, adds fault handling logic, and invokes another process to test catching the custom remote fault. The instructions aim to demonstrate how to define and handle custom faults across multiple services in an SOA composite.