I just ran across a changeset that removed addr:city from a bunch of POIs, on the grounds that it was “redundant with boundary data.” Some of these POIs had a Canadian postcode that would indeed imply city, but others had no postcode. The city could of course be calculated by the POI’s presence inside the city relation, but I hadn’t seen this as a rationale to remove information before.
Would people consider this valid? By extension, should I stop documenting the city when I create a POI; is it considered noise?
Keeping it as a source of ground truth would be nice from a development standpoint. Automated testing could then check whether over 5% (or whatever the average error is) of the automatically generated city data differs from the user submitted ones and warn you that you fucked up the auto generation.