Sacred

Sacred
A suit of armor or shield with this quality assists only wearers who have the ability to turn or rebuke undead. Sacred armor or a sacred shield increases the owner's effective level on turn undead checks by 2.

This item enhancement was introduced with Module 3 as unique item enhancement only found on Chainmail Coif, named chest item found in Sands of Menechtarun. They added this to random loot table later though, and now they are common.