VMS Help PASCAL, Attributes, KEY, Options, DUPLICATES  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  This option allows you to specify that duplicates of the key are
  allowed.

  The default for the primary key is NODUPLICATES and the  default
  for alternate keys is DUPLICATES.

  When opening an  existing  file,  the  Pascal  Run-Time  Library
  ignores this option.