The index gets reset:
 
1. When the list owner explicitly requests it.
 
2. When the list owner uses GET+PUT to edit an archive file.
 
3. If an error is detected in the  index (for instance, if it refers to a
   file that no longer exists).
 
4. If the LISTSERV administrator erases the file directly.
 
It  is not  reset when  digests are  issued, or  during any  other normal
processing.
 
  Eric