Information about what information can be stored in OSM?
OSM is primarily a geodatabase, so every information must have a connection to a physical location.
POI attributes are stored as tags on OSM objects.
At first, some technical specs about a tag:
- Tags are key-value pairs, written as “key”=“value”
- Tags are free text, but for the most used features, tagging standards have been developed.
- Language for machine-readable tags is English.
- Established tags are documented in the OSM-Wiki.
- Even values (like maxspeed=30) are treated as text internally.
- Maximum length for either key and value are 254 characters each.
- Everything is UTF-8, you can use any language and characters available worldwide.
- For keys, using other than ASCII (subset) is discouraged.
- Free-text values (e.g. street names) can be suffixed with a language on the key, to allow multilingual values.
- Only text can be stored (and has to be human readable) - for ‘data’ like images, you can set a link to an external storage instead.
So which type of information is accepted in OpenStreetMap? - See Good practice.
- ‘Ground truth’ data - things that can be verified on site.
- Static things that live ‘longer’, -> no events.
- Only objective classifications (e.g. this street is 5m wide)
- Links pointing to other services where more information is provided (A restaurant’s website, Wikipedia entry)
Which are not?
- Subjective meanings, where no common agreement exists (e.g. this is a dangerous district at night)
- Ratings (Bad food in this restaurant)
- Attributes that cannot be verified independently.
- Fictional stuff (e.g. the place where Harry Potter was born)
- ‘Virtual’ connections between POIs, e.g. value flows.
- Historical features no longer visible (e.g. if a building has been razed, it should be deleted in OSM too)
- Temporal stuff like events. Some exceptions to occur for big events where maps of the site are useful, e.g. for Burning Man Festival.
- ‘catchment areas’ like wifi coverage or delivery radius of a food coop.
- Alphabetical list of all Tags where a description exists in the OSM-Wiki: Map Features.
- Taginfo – a site to explore current tag usage in the OSM database.
- Create Any Tags you like.
- The proposal process to make new tags kind of ‘official’.
List of common tags:
- Address: addr:*=
- Names (name, alt_name, old_name, official_name, …)
- contact: data. (website, email, phone, fax, contact name, social media sites, …)
- for ‘Main tags’ like amenity=, shop= see the OSM-Wiki: Map Features.
- wheelchair usability
- smoking allowed
- cuisine=* for restaurants etc
- Opening hours
- text description (use only for information where no machine-readable established tag exists)
- organic, fair_trade, second_hand (=only/yes/limited/no) classification for shops/restaurants etc
- diet:*= for tagging where you can get food according to your needs (e.g. gluten_free, or vegan)
- access restrictions (e.g. only for members, or private access)
- start_date (‘founding’ date of POI)
- wikipedia, wikidata= for links to WP or Wikidata
- image=http:// … link to image for POI
- fee=yes/no does it cost money to use it? (e.g. parking lots)
- payment:none=yes can you get something for free here?
- owner specify (which company?) owns the business
- operator specify the operator’s name (e.g. for franchises)
- brand - (e.g. T-Mobile for a telephone cell)
- internet_access available
- payment:* methods available (cash, bitcoin, credit cards etc)
- level - in which floor is it. there are also a lot more 3D-mapping tags (mainly for buildings)
Special tags for internal use:
- “source” for describing where is this information from
- “note” - a note to other mappers (e.g. Yes, the name it is really spelled with a “Deppenapostroph”)
- “fixme” - a hint to other mappers that this needs further investigation/refinement
And a LOT more… feel free to add here or propose new ones to OSM!
There are some TransforMap tags in development for proposal in OSM.