[Tagging] The actual use of the level tag

[Richard]

On Sun, Jan 20, 2019 at 07:37:23PM +0100, Tobias Zwick wrote:
> > So from a SIT perspective, the problem isn't that the US (and other
> > places) call the ground level "1". It's that the level below that is
> > called "-1" rather than "0". You could still make it compatible with
> > Simple Indoor Tagging by adding a skipped_levels=0 tag to the building,
> > but this tag has only been used five times so far.
> 
> skipped_levels is also pretty awkward because one needs to recalculate
> the indexed (OSM) level from the real (on the ground) level all the
> time. Even worse if the levels are not actually numbers on the ground
> but letters or something else (like in that mall in Bangkok).
> 
> If SIT (and by consensus in the SotM 2016 indoor session) encourages to
> use the level numbering scheme of the building operator, why keep the
> "tied to numbers" requirement?
> 
> Someone mentioned earlier in a diary discussion a pretty nice
> solution[1]. So, in a mall with the levels P2,P1,G,M,1-12,14-99 one
> simply tags:
> 
> - a shop on level M with "level=M"
> 
> - the mall building with "levels=P2,P1,G,M,1-12,14-99" (the order of the
>   levels). If levels is missing, a numerical order is assumed
> 
> - also the building with "ground_level=G" to define which level is
>   the ground level. If ground_level is missing, 0 is assumed.
> 
> I find this would have the following advantages while completely
> compatible with the current SIT scheme and has no disadvantages (I can
> come up with):

looks nice to me.. just hope that nobody needs level names with a ",".

Do we really need a ground level? I think not. We need connections to
outside ways and entrances.

Richard