/sys$common/syshlp/helplib.hlb PASCAL, Input Output, General, OPEN, File Name  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  The 'file_name' is a character-string expression containing  the
  external  file  name.  Compaq Pascal determines the default file
  name according to the environment in which you are programming.