Categories for separating waypoints in Oregon 600

I have just bought an Oregon 600 and I would like to keep my regular waypoints separate from my geocaching waypoints. I would like to update geocaching waypoints from time to time with a pocket query. This would mean deleting all of the old geocaching waypoints before uploading the results of the new pocket query (since there may be some caches archived as well as some new caches). My question is: How to create categories for all of the geocaching waypoints in one go so that I can delete them all in one go? Or is there a better way to achieve this result? I am using BaseCam 4.2.5 and have got as far a creating a new list on BaseCamp with all of the geocaches in it. Don't want to transfer them to the Garmin yet in case they get mingled with my regular waypoints. Thanks for reading