MODIFY

        LAS\MODIFY Item [Values...]

    This  is a general purpose command to edit and change the current obser-
    vation header. Some actions are merely presentation "details", others do
    affect the information in the observation. Among these, RECENTER, WIDTH,
    IMAGE and SWITCH_MODE are typically used only when the software did  not
    agree with the hardware when the spectra was taken (i.e. when the infor-
    mation in the observation header is wrong). They  should  be  used  with
    caution.

    MODIFY actions are limited. You should use the SIC\ command LET to modi-
    fy header variables which are not available within  the  MODIFY  command
    (Caution: this is the rope to hang you).