Copyright notice is a formal indication or notice of a copyrighted logo, word, or symbol along with the name of the publishers and date of publications on all the copyrighted work that is being published. It is no longer a legal requirement.
In the United States, after March 1st, 1981, a copyright notice is not a requirement for publishers. However, it is still advisable to use a notice to remind other users that the work is copyrighted and so that the future disputes may be avoided.