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 the authors of "original works of authorship" including literary, 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 U.S. copyright system and supersedes the previous Federal copyright statute. This document includes sections on: what copyright is, who can claim it, copyright and national origin of the work, the manufacturing clause, what works are protected, how to secure a copyright, publication, notice of copyright, how long copyright protection endures, transfer of copyright, termination of transfers, international copyright protection, copyright registration, registration procedures, corrections and amplifications of existing registrations, mandatory deposit for works published in the United States with notice of copyright, 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, effective date of registration, and availability of further information. (THC)