Military Payment Certificate from my time in Korea in 1972-73. Thirteen series of MPC were issued between 1946 and 1973. We called it Monopoly Money or Funny Money. After Vietnam in 1973 the only place using MPC was South Korea. In fall of 1973, an unannounced C-day was held retiring Military Payment Certificates and exchanging them for greenbacks. MPC was never issued again. The purpose of MPC was to prop up the Korean Won Currency. However, a black market existed in which dollars were sent to service men and they in turn exchanged it for Korean Won at 2-4 times value. Then Korean Won would be exchanged for MPC at Military Finance Offices. We called that supplemental income. Government called it money laundering.
Most people think that because the fractional notes were around for such a short time, that there the rarest in the series, actually that,s not the case This note is actually the rarest and like the others above from my personal Collection Series 651 $5 ( Only 1,600,000 printed ) and happens to be a Top pop 1 of 1 PCGS 68PPQ