[ghaff]

Right. Under the older copyright regime in the US, you more or less had to add the appropriate incantation/symbols and send a copy to the Library of Congress or you pretty much had no leg to stand on collecting compensation if Disney or whoever decided to rip you off. The US decided that wasn't a good thing and that works should be copyrighted automatically. (Registration still has some benefits for collecting on copyright claims.) But that also means you now need to get rid of that automatic copyright, assuming you can, if you want to do so.