We recommend that you register your script with the WGA and/or the U.S. Copyright Office. We do not require such registration for entry. We are aware that we instruct you not to include a cover page (so that readers cannot see your name) and that copyright or registration information would normally be on that page. We simply recommend that you take at least one of those steps to protect your intellectual property.
Whether you do or not, your script will still be read. At no point in the entry process do we check for registration or copyright. Our contest has been running for 20 years and we are very careful with our entrants' scripts. However, those easy steps will help ensure that your work is protected.