Comment Keep those Confidential Memos confidential (Score 1) 309
I imagine the first terms to be added could be something like "Company Confidential, Do Not Copy" or "Sensitive Business Information".
That said, copiers already block copying of certain patterns, such as US currency. With a little trial and error it's not hard to figure out exactly what on the dollar bill is being matched. Just add it to your documents, and no body will even be able to print them. (Careful, as some brands of printers will lock themselves and require a service call after you try to copy money.)