Section 180B in The Indian Post Office Rules, 1933
180B.
Broken amounts may be made up by affixing unused Indian Postal Stamps, not exceeding four in number on the face of the Indian Postal Orders or where the space on that side is not adequate on the reverse thereof; provided that the total of stamps affixed on each order shall not exceed three rupees and the total amount payable on the order shall not exceed one hundred rupees.
