This module implements the poscatboiler category tree system, which generates the descriptions and categorization for all category pages on Wiktionary (other than those with manual wikicoding, which should be converted to use the category tree modules). For historical reasons, there is a separation between the generic category tree code in Module:category tree and a single implementation in Module:category tree/poscatboiler. The plan is to merge the two into a single category tree module.

For more information, including an introduction to the category tree system and a description of how to add or modify categories, see Module:category tree/data/documentation.

The data that specifies how particular categories are handled is contained in submodules, which are directly under Module:category tree. The module Module:category tree/data lists all the submodules.

Subpages