To add to the thread. I have this example in among my Officials.
For your information, the government used sealed envelopes of this type for "Money Letters" which were sent when there was a bill to be paid but in an amount that did not, in someone's mind, warrant a cheque. I think that the Indian example has the word, "Money" in the cancellation. I suspect that banks used a similar rationale for the sealed letters. Important documents, on the other hand, were sent registered mail which, of course, cost more.


