Cameroon Aerogramme with Enclosure, Taxed as Air Mail Letter

This aerogramme (NGK Cameroon #15) was sent from BOT MAKAY (cds 29 - 10 1991) to Turku, Finland.

The aerogramme most likely contained an enclosure, as there is no message inside and it is not philatelic because of the addressee.

The aerogramme was not diverted to surface mail but taxed as an air mail letter instead.
The tax fraction “550 /450” next to the “T” handstamp points to 550 F deficient postage and 450 F first weight step international surface mail letter rate. “F XAF” indicates the currency (“XAF” is the ISO currency code of the Central African CFA franc), though this would not have been necessary.


Reference:
NGK, Aerogramme Afrika 2012