I still think it’s merely an administrative function to track the currency issue and nothing else. If the company keeps the aircraft segregated to one base there’s no need to open a new category. However because of things like out of base pickups, TDYs, E subs, etc.,, that creates a need for all 756 pilots to have a tracking mechanism to address the currency issues despite the fact the 764 doesn’t normally operate out of their base.

Lee