I have a Swiss stamp from 1959 and you can see the huge T and near the bottom there is a penciled 5-. Would the T be for postage due and the 5 in this case be the amount. I don't see any added postage however. Anyone know what is up? - Jeff
I have access to a wonderful publication, 'The Book of T', privately published by Edward Leahy in 1989, illustrating tax marks from around the world.
The first 'T' from Switzerland is one of three similar types used from 1895 until 1984. Given that the letter was being delivered to a business, there may have been a pile of covers and the top one would get the taxing for all those below it.
The second marking, from Austria, was noted by Leahy on 1951 mail. It is a large 'T', for sure. As to the lack of postage due adhesives, it is not unusual for them to be absent. There are no US markings on the card.