simple!). By current law, copyright begins when the work is created and is in effect for the duration of the author's life plus 50 years.

You aren't required to put a copyright notice on the work or register it with the U.S. Copyright Office, although there may be good reasons to do so.

Q. OK, I'll bite. Why would I want to?

You might want to register a work with the U. S. Copyright Office because you can only bring a lawsuit for infringement on a work that's registered. And since registering a work only costs $20, the rule of thumb is that you should register any work that's potentially worth more than $20 to you.

You probably wouldn't want to go to the expense and trouble of registering every article or letter you write, however. But just putting a copyright notice on a work may protect some of your rights. More important, it serves as notice to readers that you do care about your copyright and you don't want your work copied, stolen, borrowed, or otherwise abused.

Q. Wait -- does that mean I can't write a research paper without violating someone's copyright?

No, don't worry. Copyright only applies to the expression of an idea or fact; you can't copyright the idea or fact itself. So you can safely use the fact that cats have three eyelids in your research, even though you read it in a copyrighted newspaper article or looked it up in a copyrighted encyclopedia.

You can also quote directly as long as you follow the rather murky rules of "fair use." The doctrine of "fair use" allows people who don't hold the copyright to a work to use portions of that work anyway. The doctrine's purpose is to keep copyright laws from stifling the very creativity they were designed to protect. For writers, the doctrine of fair use generally permits quotation of short excerpts of a work in a review or criticism, in a scholarly or technical work, or in a parody. A use is more likely to be considered "fair" if it's for educational or nonprofit purposes