Isle of Man, half penny, 1981. World Food Day (WFD).
I believe this coin did circulate. From 1971 to 1979, the Isle of Man showed its name on the reverse of its coins. From 1980 onward, it was displayed on the obverse. However, you can see that the WFD design, seen above, was first issued in 1977 (seen below):
Back then, the territory name appeared on the reverse. You can see that the reverse of the 1981 coin was simply an amended version of the 1977 design. But by 1981, the territory was displaying its country name on the obverse. So, that 1981 coin is an anomaly and perhaps a bit of an accident.
Actually, the Isle of Man pound coins
did not show the territory name on the obverse until 1988. So, that was another anomaly: