[Openstreetmap-dev] OSM's Schema - moving it forwards.

[nick at hogweed.org]

> > I think there is a case for standardising at least some of these keys
> > and values, after agreeing on a common scheme. In particular, name and
> > class, and also, arguably, accessibility to foot, horse, bike and car
> > are fairly fundamental properties.
>
> I don't think so.
>
> > So we could have, in a future version:
> > <node name="Red Lion" class="pub"/>
> > or
> > <segment from="249999" to="250000" name="Smith Road" class="secondary"
> > car="yes" foot="yes"/>
>
> It would make parser, the underlying xml schema and changes to the
> meaning of the tags more difficult without any noticable advantage to
> me. There was already a discussion about this some month ago in the
> list.
>
> Please, can you explain WHY you want to have specific tags instead of
> the general way of specifying attributes?
>

OK just my 2p worth on this....  :-)

I think there are fundamental properties that occur in almost all cases and it 
simply makes sense to have them as attributes in the schema. Almost all roads 
and streets have a name, hence name should arguably be a fundamental property 
of a street and/or a segment. Similarly points of interest will all have a 
name, so again name should be arguably a fundamental property.

The trouble with no standard attributes is clients will never know exactly 
what to expect.  XHTML tags have a standard set of attributes so that if we 
want to write XHTML, we can follow standards and we know that (hopefully!) 
browsers will treat them correctly. Similarly surely an OSM XML format should 
deserve such a treatment and have a standard set of tags and attributes which 
OSM clients can understand and deal with appropriately (in addition to room 
for people to specify their own tags in the same way as currently)? I believe 
one of the Birmingham guys is drawing up such a schema and it would be good 
to reach a consensus based on this.

Nick