I recently got this Brunei cover with A.V.2 mark on it. In ebay there're several North Borneo covers that appeared with the same circular mark, and I managed to get another one. A.V.2 stands for "Avion 2", a UPU term that signifies that the letter arrived at a transit point and had to be forwarded by air to its intended destination. It appears in airmail letters of certain countries between 1940s to 1960s. During and after the war, many countries tried to avoid the war zones routes and resulted in longer route requiring transits. A.V.2 is then applied on a letter on top of the bundle in the transit point, explaining the relative rarity of such postmark. The equivalent mark for A.V.2 is the O.A.T mark (usually in red) which means "Onward Air Transmission".

A.V.2 and O.A.T marks are virtually the same. Murray Heifitz did a pioneering research on these and published his findings in the Airpost Journal (from American Airmail Society) in December 1992. According to him, A.V.2 mark was used in Singapore, Hong Kong, Bangkok, Amman, Cairo, Tripoli and San Francisco from 1940 to 1957, and later in other places such as Prague in 1966. The O.A.T marking was used in London, Prestwick, Tangiers, Hong Kong and Amman from 1940 to 1945. Of these two, Heifitz estimates that about 1000 to 1500 of A.V.2 marks exist in collectors' hand (maybe even higher) while many more of letters with O.A.T mark exist, making the A.V.2 mark relatively rarer than the O.A.T mark. He lists 20 types of A.V.2 mark and 15 O.A.T marks based on about 500 letters.

Collecting A.V.2 mark

Because there are about 20 types of A.V.2 used in countries like Singapore, Hong Kong, Thailand, Jordan, Egypt, Libya, the US etc., this should be an interesting area to explore and collect, knowing the fact that only letter on top of the bundle receives the marking, making it quite rare. The O.A.T mark is probably not as common as the A.V.2 mark with regards to letters from British Borneo (N.Borneo, Sarawak, Labuan, Brunei) but discovery may still be made! Happy hunting.