[Tagging] Discussion about Multivalued Keys

[Marc Gemis]

On Wed, Jan 27, 2016 at 6:58 PM, Colin Smale <colin.smale at xs4all.nl> wrote:
> Excluding the argument that "that's the way it is now, why change", are
> there any arguments in favour of a value-based approach? If we were looking
> at this problem as if we were designing OSM on a clean whiteboard, what
> reasons are there to say that that the "multivalued keys" problem is best
> addressed in the Value domain?

For destination:lanes you could have Paris|Rome;Milan|Berlin;Munich
for 3 lanes with different destinations. The middle lane has
destinations Rome and Milan.  I have no idea how you can solve this
with a key based approach:  destination_1:lane_2 = Rome ??

Also the semi-colon is used a lot as separator in the opening_hours tag.

Even if we are not considering solutions, please add the functional
specification for destination:lanes and all xxx:lanes (e.g.
turn:lanes) to the list of things to consider.



I thought of some extra examples of things needing multiple values

sport=multi needs a solution
traffic_calming in case  of e.g. a table + choker combination
street names for streets that form the border between 2 villages and
have different names on both sides
surface, e.g. concrete lanes with cobblestones in the middle, or a
track that is half dirt half asphalt for cyclists.