As a further example, defibrillator boxes often have postcodes to describe their location and some have taken to expand to that to addr:* tags. As with similar objects, and to echo comments above, I think the consensus is if they're not places capable of receiving mail (tip: is it even a building?) then addr:* tags should not be used, but postal_code is acceptable for a common way to geolocate them.

I will see if there's a thread in the talk-gb archives about this. I'm sure it's been raised before.