A fair use disclaimer is where you state that you're using certain copyrighted material under the Fair Use Act. This helps protect you from being accused of copyright infringement.
While using copyrighted work can lead to copyright infringement issues, the "Fair Use" doctrine is an exception to this.
Under the "Fair Use" Act, a copyrighted work can be used, cited or incorporated within another author's work legally without needing a license if it's being used explicitly for things like news reporting, researching purposes, teaching, commentary, criticism, and other such uses.
Things like movie reviews that quote the movie, or using sections of a published book for a teaching lesson in a classroom are examples of common scenarios that are protected under this act.
