The DoesAllowUnschematizedProperties method is received by the server in an RPC_REQUEST packet. In response, the server returns whether the corresponding IAppHostElement supports IAppHostProperty objects.

 [propget] HRESULT DoesAllowUnschematizedProperties(
   [out, retval] VARIANT_BOOL* pfAllowUnschematized
 );

pfAllowUnschematized: Contains a Boolean that indicates whether the element supports unschematized IAppHostProperty objects.

Return Values: The server MUST return zero if it successfully processes the message that is received from the client. If processing fails, the server MUST return a nonzero HRESULT code as defined in [MS-ERREF]. The following table describes the error conditions that MUST be handled and the corresponding error codes. A server MAY return additional implementation-specific error codes.

Return value/code	Description
0X00000000 NO_ERROR	The operation completed successfully.
0X80070057  ERROR_INVALID_PARAMETER	One or more parameters are incorrect or null.