How do red and green lateral buoys mark a channel differently in IALA Regions A and B?

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The International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA) Maritime Buoyage System uses lateral buoys to mark the edges of channels. The colors of these buoys are reversed between the two IALA regions when proceeding in the direction of buoyage (approaching a harbor from seaward).1

IALA Region A

Region A includes Europe, Australia, New Zealand, Africa, the Persian Gulf, and most of Asia.1
* Port (left) side: Indicated by a red can-profile buoy with a red light.1
* Starboard (right) side: Indicated by a green conical buoy.1

IALA Region B

Region B includes the Americas, Japan, Korea, and the Philippines.1
* Port (left) side: Indicated by a green buoy.1
* Starboard (right) side: Indicated by a red buoy.1

In both regions, the direction of buoyage is defined as the direction taken when approaching a harbor from seaward or following a clockwise direction around a landmass.1