Where can I put the stamps?

Stamps are usually pasted on the upper right corner of the front of the envelope, but there are some special circumstances: first, when they exceed the real box, more than two stamps can extend to the range of the dotted box; Second, more than two stamps (especially international letters with high and low denominations), if all of them are pasted on the front, may affect the reading information of the receiver and sender and the reading (retrieval) of the postal code. /question/555096497