[OSM-dev] JOSM: Several tags with same key

[Matt Amos]

On Fri, Apr 3, 2009 at 2:05 PM, Ed Loach <ed at loach.me.uk> wrote:
> I've been noticing recently how things seem to be heading.
>
> Before I was involved with the project there were nodes, segments
> and ways. Whether there were also relations at that time I don't
> know. Perhaps the same key could be used more than once on a way -
> again I don't know.

it was just nodes, segments and ways - relations came along at the
same time as segments were dropped in API 0.5.

this move combined a renaming with a generalisation of the data model.
previously segments had been limited to two nodes and ways could only
contain segments. in 0.5 segments became ways and could contain any
number of nodes. ways became relations and gained the ability to
include nodes directly as well as other relations. now we seem to be
moving more and more of the "way" properties onto relations (which are
getting ordered members in 0.6 to further support this) which is, in a
sense, completing the cycle :-)

cheers,

matt