The Department must preserve all correspondence pertaining to the requests that it receives under this subpart, as well as copies of all requested records, until disposition or destruction is authorized pursuant to title 44 of the United States Code and applicable records disposition schedules, including the General Records Schedule 4.2 of the National Archives and Records Administration. The Department must not dispose of or destroy records while they are the subject of a pending request, appeal, or lawsuit under the FOIA.