Langbahn Team – Weltmeisterschaft

Wikipedia:Category math feature

See: Wikipedia:Category intersection for a more recent proposal.

This is a proposal advocating the implementation of category math feature to the MediaWiki software on the English Wikipedia. Category math feature allows Wikipedians to list categories by intersection, union and subtraction. A typical Wikipedia user could find the intersection of two or more categories to be useful and efficient.

Examples:

The concern for this well favoured top-level concept would be how it would be implemented; how it would affect the performance of the live Wikipedia.

Wikinews have already implemented something like it with meta:DynamicPageList.

The {{child actor birth date}} template automatically categorizes actors into:

actors who are currently children (under 13)
teenaged actors (13 to 19)
former child actors (over 19)


Category math syntax

What are the actual specifications for the category math syntax?

See also