DEFAULTSORT - Category Intersection, Union, Etc.

Category Intersection, Union, Etc.

See also: #Searching for articles in categories

Various MediaWiki extensions allow intersection of categories, union of categories, display of info about the pages in a category, and more:

• Semantic MediaWiki
  • Main Page - start page
  • Introduction - allows further intersection with sets of pages defined in terms of relations and attributes
  • Inline queries - provides relation- and attribute-related info about the selected pages and in-page display on any page of categories the same or another page is in*Forum
  • intersection of categories and complements of categories
  • provides the time of last edit for each page
• Category-/Linkintersection - a toolserver tool to query articles based on boolean expressions of their categories (and, or, not).

They all also allow further restriction to a namespace; some allow also restriction to a union of namespaces, or the complement of a union of namespaces. They all allow the info to be displayed in any page, not just a separate category page.

See also Wikipedia:Category intersection.

For category flattening (displaying the articles in a category's subcategories, sub-subcategories, etc.) see *category flattening with Semantic MediaWiki. See also m:Category flatten, and Wikimedia bug 1497.