I am freshening up my keywords in LR. I noticed that I have several -- a whole bunch actually - that I consider pollution that I have traced back to some images I bought off a stock site. Looks like they were added to my keyword list when I imported those photos into my catalog.
I cannot seem to find an option in the preferences to _not_ add keyworks to my list on photos I import from other sources ? Am I missing something ?
You can apply those settings in the "Apply during import" section in the import screen using the "Metadata" setting. Just create a profile there and make sure you check the "keywords" option and leave it blank.
Haven't tested myself but I'm pretty confident this should do the trick!
Another thing you perhaps know already is you can purge your unused keywords quite easily by going to "Metadata -> Purge unused keywords" in the menu bar of LR.