Backplanes are normally used in preference to cables because of their greater reliability. In a cabled system, the cables need to be flexed every time that a card is added to or removed from the system; and this flexing eventually causes mechanical failures. A backplane does not suffer from this problem, so its service life is limited only by the longevity of its connectors. (Wikipedia)

If an FC-AL backplane filler panel is installed, remove the three Phillips screws securing the filler panel to the backplane and remove the filler panel from the system. (Sun Microsystems, Inc.)

If you are using a standard AT power supply and want 3.3V on the backplane, you can specify the on-backplane 3.3V power supply option. (embedded-pc.microbus.com)