It sounds to me like its not a loss of functionality that we are
trying to avoid, but the requirement appears to be explicit
interoperability between LPR clients and IPP servers. Wherein there
is some type of "gateway service" that maps LPR "config file"
statements to IPP attributes so that IPP servers emulate LPD
servers for potential LPR clients.
I am assuming that the gateway support only supports those
"config file" options that are specified in RFC 1179, and that
any additional vendor-specific add-ons, no matter how prevalent
they may be, will not be mapped. These unknown attributes would
be ignored by IPP LPD-gateway services.