[Talk-GB] OSM UK address project: tags

[Colin Smale]

> On 12/22/2021 12:13 PM Mark Goodge <mark at good-stuff.co.uk> wrote:
> > On 22/12/2021 10:28, Colin Smale wrote:
> 
> That said, because of the way that OSM's data is structured (unlike the 
> PAF, it isn't a flat file),

Not in terms of storage, but in terms of data structure the tagging scheme for addresses is essentially a simple table with many columns which may or may not be filled with data. The PAF model has many fields, and it sounds like we are trying to map them onto a smaller set of fields without losing any information. Not an enviable task.

  we aren't tied to RM's structure in cases 
> where it's clear that our tags can give more useful information. A 
> specific example of that is a house I used to live in, which has a 
> postal address of
> 
> Flacks Farm
> 43 Sedge Fen
> Lakenheath
> Brandon
> Suffolk
> IP27 9LG

Royal Mail say it's just:
43 Sedge Fen
BRANDON
IP27 9LG

Which highlights another problem area: the human factor. People's perception of an address, including their own address, may differ from Royal Mail's. These days RM only actually require a very limited number of fields - county is completely redundant for example. The goal of an address in their view is to uniquely identify a letter box, and it doesn't need to include any information about either the location of that letter box or a route to get there. There's a lot of tradition and nostalgia involved. What's the "ground truth" (in OSM terms)? If the resident says the address includes "Lakenheath" but Royal Mail say it doesn't (or doesn't need to), what do we do? In this specific case it is possibly harmless redundant information, but this will not always be the case I fear.