|The ID of the Wikidata item about the feature.|
|Used on these elements|
|Tools for this tag|
The ID of the Wikidata item about the feature (for example, Q9141 represents the ). Like wikipedia=* only entries which are 'about the feature' should be linked. A link from St Paul's Cathedral in London to an entry about St Paul's Cathedral is fine. A link from a bus depot to the company that operates should use operator:wikidata=* instead, link from monument to event that is memorialized should use subject:wikidata=* instead.
For entries with both wikipedia=* and wikidata=* these links should be equivalent, except if Wikidata has a more precise entry, which corresponds better to the OSM object than the Wikipedia article does. In that case the relation between both (The Wikidata entry and its parent wikidata entry, connected to the WP entry) should be described on Wikidata, through a "part of" property.
Finding a Wikidata ID
In order to add a Wikidata tag, you first have to find the item ID. An ID always begins with Q, followed by numbers. There are several ways to do so.
Search on the Wikidata homepage: www.wikidata.org. Now you can copy the id from that page. Alternatively you can extract the ID from a Wikidata URL: http://www.wikidata.org/wiki/Q9141
Find a wikipedia article. If the article has a corresponding Wikidata item, you can click the "Wikidata item" button on the side menu. (See the image)
iD, the default osm web editor, automatically adds the corresponding wikidata key when the wikipedia=* key is updated. You just need to paste a Wikipedia article full url without choosing the language. See this video for an example: https://www.youtube.com/watch?v=FkqPLzIUr1k (note that you don't need to remove the previous wikipedia key)
Classes to avoid in wikidata=* tag
Instances of the following Wikidata items (and of any subclasses of the listed items) should be avoided in the wikidata=* tag:
- web page (Q36774)
- abstract object (Q7184903) (includes e.g. human (Q5), taxon (Q16521))
- animal (Q729)
- fiction (Q8253)
These types normally don't occur as OSM objects and since the main wikidata=* tag is for Wikidata items that are equivalent to OSM objects, Wikidata items of these types are normally tagging errors. However for secondary wikidata tags these classes are fine.
Adding missing items to Wikidata
Wikidata is a separate project which is freely editable in a similar fashion to OSM. If an item does not exist in Wikidata itself, you can create it But please read the notability guidelines first.
Wikidata values are now clickable on the OSM main site, and they link to the corresponding Wikidata item. example:
You may tag secondary attributes of the feature by preceding the wikidata key with the name of the attribute, separated by a colon (:). The value of such a key would be the same as the normal wikidata key, but referring to the appropriate wikidata entry.
Common secondary wikidata tags:
- Operator (not franchise) of a restaurant, shop, bank or some other customer service or office. Entity type must be organization
- Network of public transport routes.
- Brand of product (car, bicycle..) that a retailer sells or workshop repairs. e.g. BMW for a vehicle dealership/ service centre; or McDonald's for a fast food franchise outlet.
- The architect (or architectural firm) of a building or structure. It should be an instance of human or company.
- The artist/maker of statue or other artwork or memorial. It should be an instance of human (well, the way elephants are painting, we shouldn't constrain this one too much).
- The species of a plant. It should be an instance of (P31) Taxon (Q16521)
- The subject of a statue, artwork or memorial (a person, event, geographical feature, ...)
- The person, event, geographical feature or other subject that an entity (e.g. a street, airport or building) is named after. If the street has old_name=*, use old_name:etymology:wikidata=*
For a list of all secondary attributes currently being tagged with this key, see taginfo.
It may be more useful to store certain data on Wikidata. For example instead of using name:etymology:wikipedia=* or name:etymology:wikidata=* one may follow the Wikidata link and use https://www.wikidata.org/wiki/Property:P138
Occasionally, a feature may have one or more secondary links, but no primary link. For example, a memorial depicting a famous event may have only a secondary subject:wikidata=* link. Monuments, memorials, statues and similar features should have wikidata=* only if they have their own Wikidata article. The same applies to chain stores.
- the proposal
- Video guide to easily add wikidata with iD