42.7—Retention of other records.
Except as specified in § 42.6, each carrier shall retain records identified in its master index of records for the period established therein. Records relevant to complaint proceedings not already contained in the index of records should be added to the index as soon as a complaint is filed and retained until final disposition of the complaint. Records a carrier is directed to retain as the result of a proceeding or inquiry by the Commission to the extent not already contained in the index will also be added to the index and retained until final disposition of the proceeding or inquiry.