77a8603f_ervation__Library_of_Congress___Definition
[Term] Preservation copy [Definition] 
Digital content targeted for preservation that is considered the master version of the intellectual content of any arbitrary digital resource. Preservation master files may capture additional information about the original beyond the content itself. Because they are created to high capture standards, preservation master files could take the place of the original record if the original was destroyed, damaged, or not retained. Preservation masters generally do not undergo significant processing or editing. Preservation masters are often used to make other copies including reproduction and distribution copies.
NDSA Levels of Preservation Glossary - National Digital Stewardship Alliance - Digital Preservation (Library of Congress)
Definition