Module:Category handler/data/doc

This is a documentation subpage for Module:Category handler/data.
It may contain usage information, categories and other content that is not part of the original module page.

This module is used in conjunction with the category handler module to manage categories; it is a very important template used on millions of pages.

This Lua module is used in system messages, and on approximately 4,770,000 pages, or roughly 8% of all pages.
Changes to it can cause immediate changes to the Wikipedia user interface.
To avoid major disruption and server load, any changes should be tested in the module's /sandbox or /testcases subpages, or in your own module sandbox. The tested changes can be added to this page in a single edit. Please discuss changes on the talk page before implementing them.