This challenge that was recently published in my area, and I found it. When I found it, unbeknownst to me, it had been disabled (but, the cache was in fine shape). This challenge has now been archived. The reviewer who archived it wrote:
"Archiving as it is (more!) apparent that this Challenge isn't actually Guidelines compliant (oops) as it is based on geographic areas other than countries, states/provinces, counties (or their local equivalent). Thanks to <CO> for being so understanding at my Publish-oops and suggesting an Archive is a workable resolution option."
To me, this is an *extremely* narrow interpretation of rule #10's point: "Challenges based on geographic areas other than countries, states/provinces, counties (or their local equivalent). Examples: user-defined mapping polygons, latitude/longitude, radius, etc." I wouldn't count the distance between finds as a 'geographic area' - it's a distance. Regardless, in this interpretation, ANY challenge that uses distances between finds would be disallowed - for example, cache-to-cache distance challenges (eg. to-the-moon challenge), chain challenges, NSEW area challenges, etc. etc. I have one such challenge myself, that would assuredly not be allowed under this interpretation (but was published within the last year).
Does anybody know if this is an "activist reviewer", or official Groundspeak policy - and if there's somebody at HQ we can ask for clarification? I'm assuming the former, because it would be a little sad if we lost all challenges based on distances... but if so, it would be nice to know so we don't keep making checkers for them.