Warning: Unrecognized control line

Problem:

After checking my logfile, I see "Warning: Unrecognized control line." What does this mean? And, is it going to cause problems in the future?

Answer:

An unrecognized control line means that your LPR is sending over code for RPM Remote Print Manager™ to use when printing. These are "enhancements" to the System V printing system. The System V printing facility supposedly expands the functionality of the BSD spooling facility, however, these enhancements have not been documented.

RPM handles these "enhancements" by simply ignoring the option. If you have told your printer to use a form (for example), it simply will not be used. This option will just be ignored. You should be able to eliminate these by editing the printcap file.

Currently, RPM handles only basic commands from the LPR. If you wish to know which commands RPM recognizes, consult the RFC1179 specifications.