WoW Item Upgrades
More commonly referred to as "upping"--are enchantments and items that can be put on weapons and armor pieces, increasing their stats. These upgrades can increase the gauge of an item upgrader kit by a certain number of points. Their costs scale with their rarity.
The melee PvP scene highly values the perfect roll of the armor for its ability to minimize weapon damage.
Type-restricted upgrades
Upgrades are an essential element of the crafting process. Upgrades can enhance the stats of an item upgrader mod or enhance its strength, or even provide a bonus effect. They can also alter the item level upgrade's appearance. While certain upgrades are universal, others are governed by specific rules when applied to armor or weapons. The wrong upgrade can ruin the weapon that was previously amazing, or even render it unusable.
In general, you can only upgrade items an item upgrade of equipment to the level of its most advanced counterpart. You can only upgrade helms up to the highest level.