Map > Properties > Coordinate System: In this dialog, after clicking OK, ask "are you sure you want to change the Map View (Current XY) coordinate system. Yes or No answer required by User.
...The phrasing of the question might be a little different than that. See more about terminology suggestions below.
Anyway, the reason for this is that it's just too easy to inadvertently change this by browsing/reviewing through the coordinate system lists and clicking on something and not even realize it ...True, you can click Cancel or Exit instead of OK, but I don't believe that's totally intuitive -- because you may have very well meant to just review things. It can be particularly useful to check the 'Layers' section to see ALL of the possibly different coordinate systems in play. ...So, I might just be saying "OK" to my review.
If you just happen to click on one of the coordinate systems, then click OK, you have now changed something important -- and you may not even realize it.
With that (i feel like this is part of the same "idea"), I would also suggest NOT calling the Map View coordinate system "Current XY". When I'm teaching this to others and the Map View is set to a geographic coordinate system, some students are conceptually confused when we're dealing with longitudes and latitudes. I realize there is a correlation, but I think it would be better to keep that term "neutral" somehow. ...Why not just "Current Map Coordinate System" or something like that?
Thanks!
