HelpCustom items with a type

So I'm just wondering how would you go about to make a custom item in Fab's source that has a type eg; 0x13BA. I tried giving it a type in Addition.xml and dat1.xml but they both gave me an error, when I use ext="true" it works but I want a type for the object.

I also tried going to server/game/lib/constants.js and adding the item to that list but when I /give the item all it gives it a glitchy ART thing

Any help? Thanks