The entry-point table that is filled by an NPP when its InitialPrintProvidor function is called is implemented as the PRINTPROVIDOR structure. Entry points for functions exist in the PRINTPROVIDOR table that an NPP must implement as stubs. These entry points are included in the PRINTPROVIDOR table for use by the Local Print Provider and to preserve source code compatibility with Windows NT.
Print Providers must supply valid entry points for all functions in the PRINTPROVIDOR structure. Providers should supply stub functions that return correct error values for all unsupported functions. Unsupported functions should fail and set the last error code to ERROR_CALL_NOT_IMPLEMENTED. Setting this error code tells the PRR that your provider does not support the request and allows the PRR to try the next available provider.
The functions that a network print provider must implement as stubs are: