InvokeRegistry

ERemotableException is the exception class for exceptions that a client raises based on a SOAP fault packet that it receives from a Web Service application. The ERemotableException properties represent standard elements of the SOAP fault packet. 

Create an ERemotableException descendant to define a custom exception class for problems encountered when executing the methods of an invokable interface in a Web Service application. When a Web Service application raises an ERemotableException descendant in the course of executing a request from a client application, it adds the values of any published properties to the fault packet, in addition to the value of the Message property. Note that these published properties must be remotable types: that is, the value must be a scalar type, or it must be a registered descendant of TRemotable. 

Before the properties of an ERemotableException descendant can be transmitted in a fault packet, it must be registered with the remotable type registry (RemTypeRegistry). Call the RegisterXSClass method of the remotable type registry, on both the client and the server application, to enable your exception class to be transmitted. 

RemTypeRegistry 

TRemotableTypeRegistry 

Creating Custom Exception Classes for Web Services