Writes the system parameter values from the SYSGEN work area to a
  parameter file, the system image, or the active system.

  Format:

    WRITE filespec
    WRITE CURRENT
    WRITE ACTIVE

Additional information available:

CURRENTACTIVEDEFAULT

file-spec

  The name of a new parameter file to be created; file type defaults to PAR.

  Writes the parameter values to the current system image file,
  SYS$SYSTEM:SYS.EXE, so they will be in effect for the next re-boot.

  Writes only the dynamic parameter values to the active, running system.

  Specifies that source information is to be written to the
  default list. Requires CMKRNL privilege.