Magical cloak that acts as armor. Protection against normal and magical attacks as well as holy spells. Gives creatures who are harmed by light and sunlight immunity. Give wearer the ability to become invisible at night. Sentient and cursed. See full description for details.
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.