This illustrates, to me, that an attempt to add an ontology on top of the tagging is likely to be vulnerable to the problems it aims to solve.
Any such thing would want to express relationships, so that e.g. renderers which have never seen the tag before can say "aha, they say that I could render this like a restaurant if I haven't added an icon for it it specifically".
However, it's possible we could start to have a fairly low-key move towards ontology by simply using mediawiki categories. For example if you add [[Category:placestogetameal]] to the wiki pages for fast_food, restaurant, cafe, then it's rather likely that data consumers can use some of the pre-existing mediawiki tools (as used in http://dbpedia.org/ for example) to extract structured data that expresses tags' relations. So if you start with wiki categories you could get fairly far without having to impose a strong ontology.
This seems entirely the wrong way up. Surely much better to start with a machine-readable, properly structured, extendable, schema and fderive the human readable documentation from it, than try to extract information from unstructured data intended for human readers.
The point of a schema is to bring the documentation into the world of semantic web - share data not articles, so that programs can do something useful with it as well as people. Defaults, varying by nationality ("what's the speed limit here if it isn't stated otherwise"), descriptions in the same place in multiple languages, alternative names for tags in different languages, class hierarchies of objects, suggested related properties ("I see you're adding a post box here, you might want to add its identifier", "it's a hotel - if you can please tell us the operator, how many bedrooms", etc) and so on - rather than embedding this knowledge separately and independently and often differently in every program that works with OSM.
David _______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
