The documentation does not discuss this field. What is the purpose and usage of this field? Should it be hidden in custom forms?
It is just a yes/no field that can be used if needed. HelpDesk processes messages from any external addresses. In some cases, you might need approval of some actions from contacts whose personality and authority are confirmed. In this case, you mark such contacts as validated and add them to the ticket discussion if required. You can hide the field in the custom form.