§  42.4   Index of records.

   Each carrier shall maintain at its operating company headquarters a
   master index of records. The master index shall identify the records
   retained, the related retention period, and the locations where the
   records are maintained. The master index shall be subject to review by
   Commission staff and the Commission shall reserve the right to add
   records, or lengthen retention periods upon finding that retention
   periods may be insufficient for its regulatory purposes. When any
   records are lost or destroyed before expiration of the retention period
   set forth in the master index, a certified statement shall be added to
   the master index, as soon as practicable, listing, as far as may be
   determined, the records lost or destroyed and describing the
   circumstances of the premature loss or destruction. At each office of
   the carrier where records are kept or stored, the carrier shall
   arrange, file, and currently index the records on site so that they may
   be readily identified and made available to representatives of the
   Commission.