a member of the Universal Postal Union, but Chile
was not, and thus was not bound by
international postal conventions. Many postal irregularities were committed, including the looting of post offices and impounding of postage stamps that were often used without payment.To correct these abuses, the
Peruvian government hand-stamped
oval, triangle and horseshoe overprints to
insure that the Peruvian stamps
were sold according to the regulations of the
Universal Postal Union.