I used to work for a company that produces a well known encyclopedia as well dictionaries and thesauri and other reference works and I can tell you this practic

I used to work for a company that produces a well known encyclopedia as well dictionaries and thesauri and other reference works and I can tell you this practice makes for a lot of fun. These sort of textual watermarks make it easy to track who's copying whom across relevant sites. You can play the same game with false information, whether inserted accidentally or by design. The interesting bit is that made up dictionary terms can actually become perfectly cromulent if enough people fall for the gag.