SET ANGLE_UNIT

        [DISPLAY\]SET ANGLE_UNIT [Degree|Minute|Second|Radian|ABSOLUTE|RELATIVE]

    List or Specify the angular unit and mode used for box labelling.  The  mode
    can  be ABSOLUTE to use sexagesimal notation in Hour - Degree for  Right As-
    cension and Declination, or RELATIVE to label with offsets  in  the  current
    angle unit.

    SET ANGLE_UNIT
    will list the current and fallback units (if any)

    SET ANGLE_UNIT ABSOLUTE|RELATIVE
    will toggle between ABSOLUTE labels and relative ones in the current angular
    unit.  ABSOLUTE labeling is not possible if there is a rotation angle in the
    images: only relative labels are used in this case, whatever the mode speci-
    fied by SET ANGLE_UNIT.

    SET ANGLE_UNIT Degree|Minute|Second|Radian
    will set the current angle unit to the specified value, and enforce  use  of
    offset labels in the specified unit.