On marks

[Fiwana]

Pern's currency is known as the Mark. Marks are circulated in the form of coins made of wood, apparently as a fiat currency (though, due to Thread, wood has traditionally been a scare resource during most of Pern's history), whose value is set by a meeting of the political and economic leaders of the planet, apparently as a command economy. The coins occur in the denominations 1⁄32, 1⁄16, 1⁄8, ¼, ½, 1, 2, 5, and 10 marks, with a few 100-mark coins for very large transactions. All the coins are the same size, denominations being indicated by a stamped number. They also have some sort of picture marking representing the type of hold or craft mark they are. If the number has a line above it, then it represents a unit fraction (that is, 32 with a line above would be 1⁄32), whereas a line below the number indicates an integer. The ½ and 2 Mark coins are the only ones that could be potentially confused

All information from wikipedia's page on pern.