Metalline

Bypasses these DR types
Adamantine, Alchemical Silver, Byeshk, Cold Iron, Mithril

Doesn't bypass these DR types
Bludgeoning, Piercing, Slashing, Good, Evil, Lawful, Chaotic

History
As of Update 1, Metalline replaced Transmuting as a prefix for weapons. It still conveys its same bonus of bypassing all non alignment based, non attack type based (bludgeoning, piercing, slashing) damage reduction it did before.

Developer words on the topic

 * Won't work as Flametouched Iron
 * ''Originally Posted by Junts
 * The logic here I understand, however, there is a material that allows weapons to break dr/good (flametouched iron): why exactly can transmuting weapons not become flametouched iron and break dr/good? Is this an intentional nerf of transmuting, or an oversight regarding the material?


 * We had this discussion internally, and the end consensus was that our transmuting weapons would be able to bypass material based damage reduction - if something possessed DR/Flametouched Iron, DR/Aluminum, or even DR/Wood, it would be vulnerable to the weapon.


 * Transmuting weapons do not gain all of the properties of the materials they resemble, such as Adamantine's extreme hardness or Mithral's light weight, so we ended up deciding that neither do they gain Flametouched Iron's abilities to bypass DR/Good or to grant conditional saving throw bonuses nor Greensteel's ability to bypass DR/Evil or eat one's face.


 * - Eladrin, forums.ddo.com