Note: This page is not very active. See below for links to the active pages in this WikiProject. For current information about categorization, see: Wikipedia:Categorization.

The main project is Wikipedia:WikiProject Categories. Its sub-projects are listed below. Volunteers to these projects are very welcome.

Categorization policy

• Wikipedia talk:Categorization is where categorization policy is discussed
• Wikipedia talk:Categories for discussion is for discussions related to policy about deleting, splitting or merging categories.

Finding uncategorized articles

• Category:Uncategorized pages
• Special:Uncategorizedpages displays an alphabetical list of pages that are not categorized. It is cached (which means it may be slightly out of date) and is not editable. Discuss on Wikipedia talk:Special:Uncategorizedpages.
• Wikipedia:People by year/Reports/No other categories
• Wikipedia:List of lists/uncategorized

Cleaning the category system

• Wikipedia:Category deletion policy lists the rules, in particular the case of a category corresponding to a template.
• Wikipedia:Template messages/Deletion covers important related deletion templates.
• Wikipedia:Categories for discussion list categories that need renaming, merging or deleting.
• Wikipedia:Categories for deletion/resolved has a number of interesting precedents for naming conventions.
• Category:Wikipedia categories in need of attention lists specific categories that need organizing.
• Wikipedia:WikiProject Categories is a coordination point for systematic cleanup and standards.

Table of Contents schemes

There are various attempts to create a "Table of Contents" for Wikipedia. "Top-level" categories of this type are themselves added to Category:Wikipedia categories. Other schemes are listed at Wikipedia:Category schemes. The pages and categories listed generally require updating, organizing, and consolidation.

Cross-referencing projects

• Category:Years - A chronological cross-referencing project
• Category:Sources - Aims to organize information about reference sources. Spawned from Wikipedia talk:Forum for Encyclopedic Standards#Source_category

Content-specific guidelines

• Wikipedia:Categories for deletion/resolved has a number of interesting precedents for naming conventions.
• Wikipedia:WikiProject Tree of Life - Organisms by species
• Wikipedia:WikiProject Cities
• Wikipedia:WikiProject Aircraft/Categories
• Category talk:Academic institutions for guidelines on colleges and universities

Useful Tools

• Special:CategoryTree
• Category Tree
• Category Scan

Organizing it all

• WP:CBTF

Please report new category-related bugs on bugzilla and list them below.

(Bugs higher than 1775 have not been checked)

Redirects

• Categories need piping feature to list by alternative name (to show redirects next to the articles they redirect to in categories, when appropriate)
• Problem categorizing redirects

Special:Categories

• Link to Special:Categories should be customisable
• Special:Categories should be paged by letter, like Special:Allpages

Large categories

• Dealing with large categories
• On paged categories, article totals and subcat totals are incorrect
• Subcategory paging is not separate from article paging
• Table of contents for Categories

Updating problems

• changes to links in a template do not update 'links', 'categorylinks', etc for pages including it

General

• Add anchor tags to the headers used on category pages
• Characters in category names
• uncategorized pages report speedup hack
• Categories need to be structured by namespace
• Ability to filter user contributions by time (e.g. "January 2003") or category
• syntax to transclude a page without the containing page inheriting categories, interlanguage links
• Category page listings have unbalanced columns
• automatic edit summary for categorizing pages
• RSS feed for category updates
• Whitelist doesn't work correctly for categories
• Feature request: boolean search in categories
• Page move updates categories with sorting tweak
• Feature request: Category reverse sort by date
• Korean wikipedia's categories need new sectioning scheme
• Ability to watch all articles in a category
• can't edit the history versions of the categories!
• Request: parameters in categories

Browsing categories

• Portal:Contents - A large navigation page that includes links to high-level categories
• Special:CategoryTree - CategoryTree browser
• Wikipedia:CatScan
• Special:Categories - Lists all existing categories alphabetically.
• Category:Wikipedia categories - List of top-level categories. Requires this category be defined on the top of a tree.
• Category:Main topic classifications

Maintenance

• Wikipedia:Categories for discussion
• Special:Uncategorizedpages
• Special:Uncategorizedimages
• Special:Uncategorizedcategories
• Special:Unusedcategories
• Special:Wantedcategories
• Special:Mostlinkedcategories

Other

• Help:Category
• Wikipedia:FAQ/Categorization
• m:Categorization requirements (original guidelines for category proposals and implementations)
• Category:Knowledge representation - Material related to concept categorization.
• Wikipedia:Category intersection, proposal
• s:EB1911:Classified table of contents — Introduction (Wikisource) Technique of categorization for the 1911 Britannica
• Wikipedia:Categorization/Gender, race and sexuality
• Wikipedia:Categories, lists, and navigation templates
• Wikipedia:Categorizing redirects