/sys$common/syshlp/helplib.hlb FORTRAN, Statements, OPEN, BUFFERCOUNT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  BUFFERCOUNT = bc

  bc  Is a numeric expression whose value specifies
      the number of buffers to be associated with the
      logical unit for multibuffered I/O.  The range
      for "bc" is 1 to 127.

  If you do not specify BUFFERCOUNT or you specify 0, the system
  default is assumed.