This is the file directory for user information

LSR1 LOCK is used by INQUIR to prevent more than one INQUPD from trying
  to update the data base at once.  The data base is locked when
  LSR1 LOCK is open for writing.

LSR1 > is the most recent valid copy of the INQUIR data base.
  Do not alter that file with anything but INQUIR unless you
  know what you are doing.
LSR1 NEW is a new version being written.
LSR1 OLD and LSR1 OLDOLD are the next 2 older versions.
LSR1 2, if it exists, means that an INQUPD crashed while renaming
  versions.
  However, the situation is under control and will be cleaned up
  automatically by INQUPD the next time it runs.

.UPD1. and .UPD1$ files are updates sent by INQUIR, but not yet stuck
  into the LSR1 file.

INQUIR UPDATE is an archive of all the INQUIR updates done.  WHen it
  gets large, rename it to OUPDAT >.  Only a few months of OUPDAT
  files need be kept around.

ULIST > files are output from the INQUIR command ULIST.  It is OK
  to delete them if they are more than a few days old, since they are
  easy to regenerate.

SETMSN is a program run by the default .DDT. (INIT) file.  It
  sets the user's msname according to the FILE DIRECTORIES item in his
  INQUIR entry.