A few main post offices used the small-round postmark on a trial basis from autumn 1877, and it was introduced generally from 1878. The main function of the small-round was as a datemark on envelopes, while stamps were cancelled by the number cancel. But on printed matter and postcards the small-round was to function as cancellation on stamps of lower denomination. Small-round cancels from 126 post offices are known, including the postal agencies of Singapore and Penang. The small-round postmark was discontinued in 1893 when the square circle cancel was introduced.