Blue Triangle Air Letters

[Colin Tabeart]

I have a couple of items written from HMS Bherunda, the shore base at Colombo April & May (1945 I think, but year not stated). Can anyone tell me please: when these "honour type" air letter forms were first issued; were they allowed to go free of postage (or was postage included in the purchase price); does "IAFF - 1083 (Triangle) have any significance; why were they called blue triangles?
Thanks, Colin

[Nick Colley]

See a previous thread I started, Colin:

http://www.forcespostalhistorysociety.org.uk/smf/index.php?topic=1166.0

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