§107 · Limitations on exclusive rights:
Fair use40 Notwithstanding the provisions of sections 106 and 106A, the fair use of a copyrighted work, including such use by reproduction in copies or phonorecords or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. In determining whether the use made of a work in any particular case is a fair use the factors to be considered shall include—
(1) purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;
(2) the nature of the copyrighted work;
(3) the amount and substantiality of the portion used in relation to the copyrighted work as a whole;
(4) the effect of the use upon the potential market for or value of the copyrighted work.
The fact that a work is unpublished shall not itself bar a finding of fair use if such finding is made upon consideration of all the above factors.
Fair Use Evaluator by by Michael Brewer & ALA Office for Information Technology Policy
https://librarycopyright.net/resources/fairuse/index.php
Orphan work is work that could be anonymous, owned by a company no longer around, or the copyright owner can not be located or contacted. Orphan works may not be used often for fear of criminal penalties. After the Copyright Office completed a study they set set up a guide for orphan work. According to Hirtle etc. here is the guide.
A Webinar explaining best practice in fair use and orphan works for libraries, archives and other institutions.
ARL, Resource packet on orphan works https://www.arl.org/storage/documents/publications/resource_orphanworks_13sept11.pdf