Sentinel is a suffix that can appear on Magic and Rare Items. It provides a small magic damage reduction bonus.
It can start spawning on items at Item Level 18, but will not be able to spawn on all items until level 24.
"Magic Damage" in this case is Fire, Cold, Lightning and Magic Damage (Bone Spells from Oblivion Knights).
Magic Damage Reduced by 2
Can appear on: Magic Items, Rare Items
Is available on: Amulets, Body Armor, Circlets, Orbs, Rings, Shields