I have an NP segment at the moment that shows as just ECONOMY (N) on the main itinerary view. However, on my receipt, it shows as NP. It would be helpful if these showed up somewhere in the booking process so that when you're looking for space to use to change an existing ticket you don't need to do the search both logged in and logged out. I've found that it's much easier to get agents to find the elite inventory if you tell them that's what they're looking for.