Actually, these markings were used a lot in the Edwardian period.
Here are a couple of postcards with similar markings . The top card is a sample of domestic use and the bottom, albeit in bad shape, was used from incoming mail from the UK. I keep it for the marking only. You will also note on this one that there was a British one applied as well with a boxed T/5.
Chimo
Bujutsu
