Just a little clarification question....you can use UMD to use "Ranger/other class only" items, but not if the item specifically says in the description not to, correct?

Not all class-specific items have the explicit OOC line saying not to use it with UMD.

A few have in their description things like, "this ring will not stay on the finger of one who is not a true <class>", which is a bit more ICly-stated clue that this item cannot be worn by anything except a <class>.