There are two kinds of units called "marks" on SouCon.

Marks are the in-character currency used by characters on Pern to make transactions between each other. For more information about Pernese prices, see NEWS PRICES.

A different kind of unit is also referred to as marks on SouCon. These are an out-of-character unit used to pay for computationally expensive commands. The commands for which these are used can be listed with @list costs. Your total number of OOC marks for command running is listed by typing i or inventory.

Image taken from 'The Dragonlover's Guide to Pern' © Anne McCaffrey and Jody-Lyn Nye.