On Thu, Feb 16, 2012 at 06:25:30PM +0000, Graham Jones wrote: > <grumble> Why create a key generator:power_source rather than just use > power_source. power_source is much more generic so you could re-cycle it > for things like district heating, but generator:power_source is only ever > going to be used for generating stations, and needs a new column in the > database. </grumble>. I think I just prefer more generic, re-usable keys > rather than trying to invent a new one for each situation....
Generic key names can be confusing, especially when one OSM object is used for multiple things. Say there is a way tagged as railway and at the same time this way is part of an area tagged as a generating station. Does "power_source" mean the type of generating station or the type of power used by the railway (overhead vs. third rail vs. unelectrified)? I hope this example is hypothetical, but people do strange things in OSM... Non-generic tags also make tools such as Taginfo more useful, because each tag stands on its own. They make it immediately clear if the tagging is incomplete. If the "generator" tag got lost, how do we know what the "power_source" tag is supposed to mean? So on the one side you have generic tags like "type" and "class" and "id" which are very confusing. You never know what they belong to. On the other side you have rather complex tagging schemas like in your generator:... example. Thats sometimes hard to use, too. We still have to figure out where the sweet spot is, but I tend to prefer the more explicit keys. Jochen -- Jochen Topf joc...@remote.org http://www.remote.org/jochen/ +49-721-388298 _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk