Usage etched onto a weapon that can Parry
A kin-warding weapon can deflect attacks aimed at your allies. When you use the weapon’s parry trait, you can point it at an adjacent ally instead of defending yourself, creating a shield of runes around them. The runic barrier grants your ally the weapon’s circumstance bonus to AC, but you do not gain the bonus yourself.
The creation and application of these runes is a well-guarded Dwarven secret, and you'd be hard-pressed to find any non-dwarves that would even know where to begin.