@gurglypipe: I agree with you, but what Paul describes is the broad consensus of the UK community. 

I personally feel that defining addr:* tags as related to postal information only was a mistake: but it was exactly what the Karlsruhe scheme designers intended. It does mean that for non-postal uses of address, OSM data as it stands is less useful and needs some kind of post-processing. For a long time I've even avoided using addr:city and addr:suburb at all because of the non-obvious meanings. But, I do accept I'm now in a minority.