Dictionary.net

The © symbol, plus the date of publication and the author's name. For works published in the U.S. after March 1, 1989, no copyright notice is required for copyright protection within the U.S. or any country that has signed the Berne Convention or GATT. A notice is still useful to remind others that the work is copyrighted, to steer a would-be user in the right direction to obtain permission to use the copyrighted material and to preclude a defense of "I didn't know it was copyrighted" if someone uses the copyrighted material without permission.