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:

1. many 'instance of (P31) ' values
   • where these are obvious to most human beings looking at the item
   • Example: the statement "Elvis Presley (Q303) is an instance of (P31) a human (Q5)" does not need a source
2. occupation (P106)
   • unless it is not well-known; most people, however, are notable enough to be in Wikidata because of their occupation
   • Example: the statement that "Elvis Presley (Q303) had the occupation (P106) of singer (Q177220)" does not need a source
3. subclass of (P279)
   • similar to instance of (P31) — but used when every instance of a class is also an instance of another class
   • Example: the statement "a trilogy (Q149010) is a subclass of (P279) a series of creative works (Q7725310)" (every trilogy is a series in English) does not need a source

When the item has a statement that refers to an external source

Where the external source of information allows easy verification of the statement:

1. 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
2. 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
3. topic's main category (P910) and category's main topic (P301)
   • for items that are Wikimedia category pages
   • Example: a statement that the category's main topic (P301) is Germany (Q183) for Category:Germany (Q1410828) does not need a source

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

1. a book for its author and other information on the cover
   • for information inside the book (e.g. plot details) use chapter (P792) in the source
   • Example: a statement about The Hunger Games (Q11679) having Suzanne Collins (Q228624) as the author (P50) does not then need to include The Hunger Games (Q11679) as a source
2. a movie for its actors and other information in the credits
3. a DVD or LP record for information on the cover, including the playlist
   • for information in liner notes use stated in (P248) with liner notes (Q2263757) as the source
4. coordinates for anything you can visit or easily identify on a map, including a lunar or Martian map.

See also

• Help:Sources