I seem to have a Phantom DN who's owner I can't find and I need to remove it because I have to use that number as a Prime DN.

Any easy way to search for this Phantom DN? I'm assuming it's just setup on someone's phone as a DSS key?

Actually I was able to find it by chance just going through extensions. But it would be great to know if there is a way to search DSS keys?

No search feature. If you are onsite you could call it and listen for the ringing phones. Otherwise just hunting thought the keys is the only way.
They did add the search ability to the IPEdge.