Samsung CF21MSBU-XBM - Manual (Page 23)

On-Screen Display
1. Information button: You can see the frequency (user control
mode) used by the user, the polarity of the operational signals, the
default frequency (default mode) set when you buy the monitor and
the resolution level.
2. Exit button: Use this button to Exit the active menu or the
OSD.
3. Adjust buttons: These buttons allow you to highlight and
adjust items in the menu.
4. Menu button: Use this button to open the OSD and activate a
highlighted menu item.