This might belong in the guides section.
If you have a bunch of unid rare or legendary items in your stash for various reasons, you can copy your character to the PTR realm and ID them there.
The items will have exactly the same stats on PTR as on live.
There's not much more to it. Go check the stats on your giveaway legendaries before you giveaway an awesome item
I sincerely apologize if this is a repost.