Help:Sources/Items not needing sources
Wikidata is a collection of sourced data, which means that most statements should indicate where the data comes from.
In some cases sources are not typically required. This guideline explains when it is not necessary to add a source to a statement in Wikidata.
Please note that when data about an item is disputed then a source needs to be added regardless of whether it is included below. Furthermore, sources should not be removed from items that already have sources.
When a value is common human knowledge
Certain properties usually don't require a source:
- many 'instance of (P31) ' values
- occupation (P106)
- subclass of (P279)
When the item has a statement that refers to an external source
Where the external source of information allows easy verification of the statement:
- authority control properties
- values for authority control properties do not need a source because the values are linked to and/or automatically imported from the authoritative catalog, system, or database
- Example: a statement about Harry Potter and the Philosopher's Stone (Q43361)'s GND ID (P227) (an authority file maintained by the German National Library) or its OCLC control number (P243) does not need a source
- Commons category (P373)
- a statement about the item's Wikimedia Commons category (the category containing files related to the item) does not need a source
- topic's main category (P910) and category's main topic (P301)
Note: If a particular authority control source of information has not yet been added to Wikidata as a property, you can propose it at Wikidata:Property proposal/Authority control.
When the item itself is a source for a statement
- a book for its author and other information on the cover
- a movie for its actors and other information in the credits
- a DVD or LP record for information on the cover, including the playlist
- coordinates for anything you can visit or easily identify on a map, that includes a lunar or martian map.