Random question I've had about the NGX for about two years now but can't seem to ever find the time or resources to look up... on the Rear Overhead Panel, on both left and right IRS switches, the selectors may be rotated to ""Align", yet I have no idea what this option does. I understand how to align the IRS systems, and how they detect movement of the aircraft, but where could I find an explanation as to what the "Align" feature does/is used for??? Searched FCOM 2 for an answer but have not yet discovered one. Help anybody??? Thanks