Sec.  42.7   Retention of other records.

   Except as specified in  Sec. 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.

Specific Instructions for Carriers Offering Interexchange Services