20c aerogramme returned for additional postage, but posted underpaid a second time and sent to Pakistan on 17 March 1976. The aerogramme was initially returned to the sender for paying the missing 5c to the 25c aerogramme rate for Pakistan. Endorsed „Returned for 5c … postage“. However, the sender did not pay the additional postage and posted the underpaid aerogramme a second time.
As the aerogramme was only prepaid at 20c, it was taxed „10/15“ (double deficiency as the numerator, international surface mail rate as the denominator according to the Vienna system) when posted the second time. This is incorrect as the Lausanne system, which required the single deficiency in the numerator, was in place since 1 January 1976.
In Pakistan, based on the „10/15“ tax fraction a postage due of Rs 17 was calculated.
8½p
UK aerogramme (Greiner/Greiner # ) sent on 19 October 1975 to the US. Since 29 September 1975, the rate for the small size aerogrammes was 10½p. hence, the aerogramme was short paid 2p, which leads to 4p double deficiency in the tax fraction's numerator. The 10p in denominator is the international surface mail rate at the time of posting.
In the US, the tax fraction was multiplied with the US international surface mail rate (20c), resulting in a postage due of 8c.
Air mail letter sent 24 March 1961 to the US, franked at 3s 9d, of which 3s 6d were paid by seven cut-outs from the 1957 aerogramme commemorating the 46th Parlamentary Conference.
The 3s 9d franking paid the air mail rate for a letter weighing up to 1½ oz.
Hongkong air letter form sent 16 FEB 1956 to Yugoslavia. Since the decisions of the 1952 Brussels UPU congress came into effect on 1 July 1953, "Aerogramme" was the official name of the former air letter. As the new name had to be present on the form, it was added by a handstamp.
New Zealand Christmas aerogramme form („Issued by the New Zealand Post Office for Posting in New Zealand to Overseas Addresses“), sent from Norfolk Island (17 AP 75) to the UK. Franked at 20c.
Non-philatelic aerogrammes like this one are quite scarce
