Wikidata:Wikimedia Commons/How to help

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Wikidata:Wikimedia Commons

Introduction

There are several properties directly related to Commons:

• image (P18) (type: Commons Media File)
• Commons category (P373) (type: string)
• Commons gallery (P935) (type: string)
• Commons Creator page (P1472) (type: string)
• Commons Institution page (P1612) (type: string)

Each property points to a page on Commons in different namespace. In most cases string type properties should have following constraints:

• single-value constraint (Q19474404): each Wikidata item points to a single page on Commons
• distinct-values constraint (Q21502410): only one Wikidata item points to a specific page on Commons
• Commons link constraint (Q21510852): Link points to a valid page on Commons. Links to non-existing pages should be deleted or pages should be created on Commons. Unlike links of "Commons Media File" type, Wikidata software does not know the "string" is a link and does not support "valid-page" constraint automatically. Please support or propose alternative solutions to the proposal in Phabricator:T179937 to enforce this constraint automatically.
  Tracked in Phabricator
  Task T179937
  

The first 2 constraints enforce one-to-one nature of those properties. The only exception is Commons category (P373) which is often added to both article and category items and does not meet distinct-values constraint (Q21502410). However it should meet that constraint if we narrow it down to a single page.

We need help enforcing those constraints on Wikidata. In addition there are many maintenance categories on Commons tracking issues related to Wikidata. Those also need help maintaining.

Tasks on Wikidata related to Commons

Please fix issues reported in:

• Wikidata:Database reports/Constraint violations/P18
• Wikidata:Database reports/Complex constraint violations/P18
• Wikidata:Database reports/Constraint violations/P373

...2352635* Wikidata:Database reports/Constraint violations/P935

• Wikidata:Database reports/Complex constraint violations/P935
• Wikidata:Database reports/Constraint violations/P1472
• Wikidata:Database reports/Complex constraint violations/P1472
• Wikidata:Database reports/Constraint violations/P1612

If some of the constraints seem wrong please discuss the issue and change or remove the constraint.

Tasks on Commons related to Wikidata

Institution template related maintenance

• c:Category:Institution templates with Wikidata link: quick statements coordinates ready to be copied to Wikidata. Missing websites should be verified first
• Institution templates with information which is mismatching data on Wikidata
  • c:Category:Institution templates with mismatching linkback
  • c:Category:Institution templates with Wikidata link: mismatching coordinates
  • c:Category:Institution templates with Wikidata link: mismatching homecat
  • c:Category:Institution templates with Wikidata link: mismatching image
  • c:Category:Institution templates with Wikidata link: mismatching linkback
• Institution templates with information which is missing on Wikidata
  • c:Category:Institution templates with Wikidata link: item missing coordinates
  • c:Category:Institution templates with Wikidata link: item missing homecat
  • c:Category:Institution templates with Wikidata link: item missing image
  • c:Category:Institution templates with Wikidata link: item missing linkback
  • c:Category:Institution templates with Wikidata link: item missing website - website should be checked before addition to Wikidata, as we have a lot of dead links
• c:Category:Institution templates without Wikidata link Institution templates which might need to be linked with Wikidata

Location template related maintenance

• c:Category:Pages with local coordinates and missing Wikidata coordinates coordinates ready to be copied to Wikidata
• c:Category:Pages with local coordinates and mismatching Wikidata coordinates either pages should not be linked or one of the coordinates is wrong
• c:Category:Pages with local coordinates and similar Wikidata coordinates Similar coordinates but not matching within wikidata coordinate precision. Either one of the locations is wrong or precision is not realistic. For example, someone might have specified location of a city with centimeter precision.

Authority control template related maintenance

• c:Category:Pages using authority control with identifiers missing from Wikidata identifiers ready to be copied to Wikidata
• c:Category:Pages using authority control with identifiers mismatching Wikidata either pages should not be linked, one of the identifiers is wrong, or both are correct and both should be added to Wikidata
• c:Category:Pages with empty authority control templates Commons templates which need to be linked to Wikidata