Propagating Error Information
Propagating extended error information allows servers that receive an RPC_S_* error, or any other error code for that matter, to allow the RPC run time to propagate the information it received to its callers. All the server must do is call the RpcRaiseException or RpcAsyncAbortCall upon encountering a fatal error. The RPC run time takes care of chaining the extended error information, if any, causing the fatal error to report the fatal error itself, as long as the error code given to RpcRaiseException or RpcAsyncAbortCall is the same as the error code causing the fatal error.
Build date: 11/23/2012