Sec. 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.