The protocol type of this printer port, specified as a value from 'PrtChannelTypeTC' in the IANA Printer MIB (e.g., 'chLPDServer(8)' for LPR (RFC 1179) or 'chPort9100(11)' for Raw), or zero if not specified. Compatibility Note: The value of zero is NOT registered in the IANA Printer MIB. It is an out-of-band value. Thus the syntax of this object is NOT specified as 'PrtChannelTypeTC'. Systems that do NOT implement IETF Printer MIB v2 (RFC 3805) SHOULD use 'chPort9100(11)' for Raw printing (with an alternate port in 'ppmPortProtocolTargetPort', if necessary), because 'chPortTCP(37)' and 'chBidirPortTCP(38)' are NOT defined in IETF Printer MIB v1 (RFC 1759). Systems that do implement the IETF Printer MIB v2 (RFC 3805) MAY instead use 'chPortTCP(37)' or 'chBidirPortTCP(38)' for Raw printing, because 'chPort9100(11)' is DEPRECATED in IETF Printer MIB v2. Systems that implement any version of the IETF Printer MIB (RFC 1759/3805) SHOULD use the same value of protocol type for this port in the 'prtChannelTable', so monitoring applications MAY search for more channel information and status.