The Privacy Act requires each agency to publish notice of its systems of records in the Federal Register. This notice is referred to as a system of records notice (SORN).
Currently the National Archives requires agencies to print and attach every applicable SORN to the SF-258 when accessioning permanent records to the Archives. NARA recently implemented an Electronic Records system for transferring permanent records but the requirement to include paper SORNS was not eliminated.
The pages and cost of printing runs into the millions of dollars not including the amount of physical space taken up to store the same SORN over and over each time it is referenced.
Providing just the reference would be sufficient. Public links to the SORNs are available on the GPO website as well as in the electronic version of the Federal Register.