I also have some with K C and some with P P and P S. I can not find a library of where to look up what these are?
Look for 'DRC Error Marker Code Definitions' in the on-line help...
Ahhh.. Thank you! I could not for the life of me figure out what they were called.
Also, if your find/select filter has DRC errors enabled, you can select these flags and RMB- "Show Element". More useful information including the objects causing the conflict.