Error: Unrecognized control line

After checking my logfile, I see

"Warning: Unrecognized control line."

What does this mean? And, is it going to cause problems in the future?

RPM Remote Print Manager® processes LPR/LPD information in accordance with the RFC1179. Some UNIX systems (System V) have tried to enhance the LPR/LPD protocol above the standard RFC specifications. You most likely are using one of these particular commands to try to get the correct output. RPM handles these problems by simply ignoring them. It is a good idea to not allow these printing "enhancements". Usually you can take these extras out of the printcap file.

This issue is currently being researched. We plan to have RPM correctly use these control lines, but we currently have no confirmation as to what they specifically do. We need more information from the developer of these System V enhancements. Contact our support team for further information.