“ The size and number of knots in hair, tied around neck, or hanging from belt could signify family, importance, worship, guild affiliations. Being able to translate the meaning of the size and placement of knots can give you a a large understanding of who somebody is.
May be used in a more barbaric society. Where in cities peoples clothes and crests show who they are, barbarians have no need for this so use knots.”
“ In the dry steppelands, one of their most valuable exports is the dried sap of the Larthorn tree. These ugly plants are covered with vicious thorns, but the locals harvest the golden droplets that ooze from their bark each Autumn. This sap, once dried, is valued for its medicinal properties and as a spice. Since little gold or silver is found in the hinterland, the dried droplets of sap are often used as currency by the locals.”
“ A small, primitive village has yet to discover fire, which is a good thing because there are highly flammable (but not otherwise dangerous) gasses in the air. The heroes, blissful in their ignorance, don't know that and think it a wonderful idea to show the locals open flame.”