This circular answers some of the questions that are frequently asked about copyright, a form of protection provided by the laws of the United States to authors of "original works of authorship" including library, dramatic musical, artistic, and certain other intellectual works. The Copyright Act of 1976 (title 17 of the United States Code), which came into effect on January 1, 1978, is the first general revision of U.S. copyright law since 1909; it makes important changes in the copyright system and supersedes the previous Federal copyright stature. This document includes sections on: what copyright is; who can claim it; copyright and national origin of the work; what works are protected; what is not protected by copyright; how to secure a copyright; publication; notice of copyright; transfer of copyright; international copyright protection; copyright registration; registration procedures; effective date of registration; corrections and amplifications of existing registrations; mandatory deposit for works published in the United States; use of mandatory deposit to satisfy registration requirements; who may file an applications form; application forms (for different types of publications and different purposes); mailing instructions; fees; search of copyright office records; and availability of further information. (AEF)