The Nuclear Regulatory Commission (NRC) is amending its regulations on availability of official records in three areas. The amendments require those who submit documents claimed to contain proprietary or other confidential information to specifically mark those portions of the document containing such information to decrease the chances of inadvertent public release of the information by the NRC, codify NRC's practices and delineate the circumstances under which the agency will not return confidential documents that have been submitted to the NRC, and codify NRC's practices of making as many copies of copyrighted material submitted to the agency as it needs to perform its regulatory and licensing functions. The amendments are necessary to conform the NRC's regulations regarding the availability of official records to case law and agency practice.