/sys$common/syshlp/helplib.hlb PASCAL, Attributes, KEY, Options, ASCENDING  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  This option, along with DESCENDING, allows you  to  specify  the
  collating  sequence  for the key field.  By default, the primary
  key and alternate key are ASCENDING.

  When creating a new file, Pascal will create the  key  with  the
  collating  order  specified.  When opening an existing file, the
  Run-Time Library will verify that the existing key  matches  the
  collating  order  specified.  If neither ASCENDING or DESCENDING
  is specified when opening an existing file, both types  will  be
  accepted.