TRAIT - Saggorak
Ancient dwarven blacksmiths in Saggorak designed a series of spectacularly powerful runes. Only someone with legendary proficiency in Crafting, or a Well-Versed dwarven crafter from the city of Kovlar, can apply, transfer, or remove a rune with the Saggorak trait. Because of their considerable power, all Saggorak runes take up two property rune slots, and consequently they can be applied only to armor and weapons with at least a rune.
Source: Pathfinder #148: Fires of the Haunted City pg. 73