The following notes have been made in attempt to understand how categories currently work in WP and how the guidance (e.g. WP:DEFINING) can be improved. Comments (e.g. on the talk page) are welcome.
I've been thinking about how WP:DEFINING can be improved for a while. A good step would be to separate the guidance for categorization of articles about individual (unique) things and that for articles about concepts as IMO trying to have one sentence that covers both is the main reason why WP:DEFINING is currently so meaningless/ambiguous. Maybe something like:
Most WP articles are already categorized as per the above guidance. Many articles also have other categories (e.g. "alumni of"); the above guidance could be extended to allow such categorization where it would not cause lots of categories to be added to an article (see [1] for an example of what we don't want).
For some articles a blend of the two aspects of this guidance could be used - e.g. not every Supermarine Spitfire was a fighter aircraft (some were unarmed), but the Spitfire achieved notability as a fighter so its article can be categorized as such.
That a rule is often broken is not a good reason to rescind the rule. An analogy: in the UK the speed limit on motorways is 70mph, but many drivers sometimes (marginally) exceed it. If the limit was increased to 80mph some drivers would exceed that ...
This is a list of (some of) the types of categories that WP categorization guidance refers to. This list has been drawn up in attempt to see if any simplifications can be made and/or to avoid other types being defined.
Definition and example quote(s) using the term | Notes |
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An administration category (or project category) is a category that contains pages that are not articles, or it groups articles by status rather than content. Administration categories should not be in content categories. These categories are used mainly by Wikipedia's editors, rather than for browsing. Examples of administration categories include
Category:Wikipedia backlog and stub categories.
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A birth/death/living category - (e.g. on
CAT:NOCAT)
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A category category is a category containing categories that are not subcategories. (see
Template:Category_header)
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A container category is a
category that contains (or is intended to contain) only
subcategories rather than articles. (from
Wikipedia:Container category)
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A content category is a category that contains encyclopaedic contents. (from
Template:Category_header) (e.g. on
CAT:NOCAT)
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A disambiguation category is a soft redirect to 2 or more categories.
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This should not be confused with
categories for disambiguation pages. There is a reference to this from Template:Db-c1. |
A distinguished subcategory - see non-diffusing subcategory
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An eponymous category is a category which covers the exact same topic as an article. (
WP:EPON)
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A hidden category is ???? (e.g. on
CAT:NOCAT)
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A holding category is ??? (e.g. in the text of
Category:National Register of Historic Places articles needing infoboxes)
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This CFD deleted a holding category. |
An intermediate category is a category used to organize large classes of subcategories, such as
Category:Albums by artist.(
Wikipedia:FAQ/Categories)
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An intersection category is ???
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A maintenance category is ????
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Maintenance categories are temporary categories.??? |
A navigational category is ???
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In the quoted text the last sentence should have "directly" added. |
A nationality/occupation category is ???? (e.g. on
CAT:NOCAT)
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A non-diffusing subcategory (aka distinguished subcategory) of a category includes articles that can also be found in the parent category. (
Template:Distinguished subcategory,
WP:DUPCAT)
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A parent-only category is TBD.
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A permanent category is any category other than a temporary category (e.g. on
CAT:NOCAT)
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A primary category or primary (topic level) category is ???? (from
Wikipedia:Category_intersection)
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A project category (see administration category)
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A polluted category is TBD -
Wikipedia:Database reports/Polluted categories
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A redlinked category is ????.
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A subcategory is ????. (
WP:SUBCAT)
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A set category is a category of articles on subjects in a particular class, such as
Category:Villages in Poland.(
Wikipedia:FAQ/Categories)
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A set-and-topic category is a category that is a combination of a set category and topic category.(
Wikipedia:FAQ/Categories)
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A stub category is ?????. Stub categories are temporary categories. (e.g. on
CAT:NOCAT)
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A temporary category is ????. Examples include stub categories and maintenance categories.
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This doesn't mean that the category itself is temporary. |
A topic category is a category of articles relating to a particular topic, such as
Category:Geography or
Category:Paris.(
Wikipedia:FAQ/Categories) (e.g. on
WP:CAT)
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A tracking category is a category intended to build and maintain a list of pages primarily for the sake of the list itself (see
Template:Tracking category)
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A universal category is a category used to provide a complete list of articles which are otherwise normally divided into subcategories.
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This term is (as of 2016) very little used. Perhaps it should be removed from the FAQ page. |
A wanted category isn't actually a category .... - see
Special:WantedCategories
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A Wikipedia category is a category needed for Wikipedia administrative purposes, but that is not part of the encyclopedia itself. (
Template:Wikipedia category)
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A work category is TBD.
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The quoted text isn't entirely correct - e.g. see Category:Wikipedia and some of its subcategories. |
"Normal" categories group together articles about similar topics (e.g. 19th century French painters) which can be of use to readers/editors. When such categories get large there's usually some way in which they can be split to make them more useful. The year-of-birth/death categories don't group together such similar articles, but they may be useful (e.g. for editors maintaining BLP tags) and they have low cost - e.g. they cause little watchlist noise (typically they only need to be edited when the article is created and when the person dies) and they don't cause much category clutter. Hybrid categories would have the costs without (afaics) providing much (if any) benefits. Examples of CFDs discussing hybrid categories: Wikipedia:Categories_for_discussion/Log/2017_May_28#Category:Racing_drivers_born_in_YYYY, Wikipedia:Categories_for_discussion/Log/2017_May_30#Deaths_of_Greek_people_by_year.
Reference is often made to these categories at CFD by editors who appear to be unaware that these categories are used differently to normal categories.
Question: Do these categories therefore count as maintenance categories (e.g. should they be hidden from readers) ?
Making these categories hidden would have several advantages -
However, editors may argue that the year of birth (for example) is a characteristic of the person (the subject of the article) and that hidden categories should only be for characteristics of the article itself (e.g. being unreferenced).
How many (if any) of these should be categorized under Category:Articles ?
See also: Wikipedia:What is an article?
There are 3 types of characteristics that a subject can have that determine what Wikipedia categories a Wikipedia article about that subject should be in:
These 3 types of characteristics can sometimes overlap.
A Wikipedia category is for articles that have one or more (i.e. an intersection) of these characteristics.
In addition there are Wikipedia administration categories. Many of these are hidden from readers.
Articles about specific named things (e.g. individual people) are categorised based on two types of characteristics - characteristics based on the reason(s) for notability (e.g. being a famous actor) and biographical characteristics ( year of birth, nationality etc). Articles about individual organisations, individual buildings, individual animals, specific types of aircraft etc are similarly categorised both by reason for notability and for "biographical" information (e.g. year of establishment of a company). For a few categories it may not be clear from the category name which of these 2 kinds of characteristic it is based on (e.g. Category:People with cancer, Category:Murder victims).
Articles about concepts are categorised based on what the concept is a subset of. For example the Political history article is in Category:History and Category:Politics.
Many categories are for articles that have a combination of characteristics (e.g. Category:British fighter aircraft 1930–1939 is the intersection of Category:Fighter aircraft 1930–1939 and Category:British fighter aircraft).
In addition there are Wikipedia administration categories, many of which are hidden from readers.
In November 2011 there were over 600 articles in the "Aviation terminology" category. Not one of these articles was actually about terminology (a subset of linguistics). Having an article inappropriately in a terminology category is not itself much of a problem, but there were about 100 aviation articles that weren't in any other aviation category - for example anyone looking in Category:Types of take-off and landing would not have found the article about Brodie landing system. Each article in the "Aviation terminology" category was examined and categorised more appropriately (e.g. into Category:Aircraft navigation) or deleted (e.g. by replacing with a redirect or PRODing).
Putting an article in a terminology category because the article title is a term is an easy mistake to make (I've done it myself in the past) although in many cases ( Bay of Bengal Cooperative Air Traffic Flow Management System, Aviation Maintenance Technician Day etc) even the title isn't really a term.
If an article really is about terminology (i.e. terminology is a defining characteristic of the article's subject) then, of course, it should stay in the Terminology category. Sometimes (e.g. Medical terminology) this should be in addition to a subject-based category. Wikipedia is supposed to be about subjects, not words (Cf Wiktionary), therefore the categorisation should be based on the subject of the article, not whether the article title is an acronym, terminology, phrase, name etc.
It has been suggested (e.g. Wikipedia:Stub types for deletion/Log/2011/May) that Terminology categories provide a useful way to separate articles about specific subjects (i.e. where the article title is a name e.g. Air France) from articles about generic subjects (e.g. Airline ticket). It may be useful to separate articles about specific and generic subjects, but terminology categories are not the best way to do this; normal WP practice is to put articles about specific aircraft (for example) in categories such as "... by country" and "... by decade".
Some discussions:
Related discussions:
My position:
Solutions:
Common objections:
Examples of difficult cases:
Example discussions:
An interesting thing about descent categories is how many editors involved in the creation or population of such categories have been blocked (although this may be for totally unrelated reasons).
One editor appears to have been adding ethnicity categories based solely on surnames. [1] A similar case is fixed by this .
Some examples of very specific descent categories:
Example of lots of descent etc cats: [6] [7] (added 6 descent categories), Alicia Keys (in 6 descent cats as of Feb 2016).
Example of descent categories being added for no/incorrect reasons: [8]
An example descent CFD is
Wikipedia:Categories_for_discussion/Log/2015_December_2#Category:Lebanese_people_of_Maronite_Christian_descent.
References
This shows only some of the categories (as of August 2013). Italic font indicates where changes to the category structure are proposed. This does not necessarily list categories in alphabetical order.
Category:Military vehicles ( by country, by period) Category:Military vehicles by type ( tracked, wheeled) Category:Military ambulances Category:Artillery tractors Category:Command vehicles Category:Military engineering vehicles Category:Armoured vehicle-launched bridges Category:Military light utility vehicles Category:Military recovery vehicles Category:Armoured recovery vehicles ( by country, tracked, wheeled) Category:Reconnaissance vehicles ( by country, tracked, wheeled) Category:Soft-skinned vehicles Category:Military trucks ( by country) Category:Tank transporters Category:Combat vehicles ( by country, airborne) Category:Combat vehicles by type Category:Armoured fighting vehicles ( by country, by period, amphib) Category:Armoured fighting vehicles by type Category:Armoured cars ( by country, by period) Category:Self-propelled anti-aircraft weapons Category:Armoured personnel carriers ( by country, by period, amphib, tracked, wheeled) Category:Armoured recovery vehicles ( tracked, wheeled) Category:Tank destroyers ( by country, by period) Category:Infantry fighting vehicles ( by country, by period, amphib, tracked, wheeled) Category:Tankettes ( by country, by period) Category:Internal security vehicles Category:Tanks ( by country, by period, by period by country) Category:Tanks by type ( amphib, airborne) Category:Cavalry tanks Category:Cruiser tanks Category:Flame tanks Category:Heavy tanks Category:Infantry tanks Category:Light tanks Category:Main battle tanks Category:Medium tanks Category:Multi-turreted tanks Category:Superheavy tanks Category:Tanks with autoloaders Category:Fire support vehicles Category:Self-propelled artillery ( by country) Category:Assault guns Category:Mortar carriers ( tracked) Category:Self-propelled howitzers ( tracked, wheeled) Category:Self-propelled rocket launchers ( tracked, wheeled) Category:Unmanned ground combat vehicles
Some examples of mainspace categories whose membership is not permanent:
Currently (August 2014) we have two separate category trees for stub articles -
So, for example, we have both Category:Airport stubs and Category:Stub-Class airport articles. This, IMO, is an unnecessary complication in Wikipedia - in checking categorization I've found several cases where an article-side stub category was placed in a wikiproject category ( example) or a talk page stub category was placed in an article-side stub category ( example). Note: Any overlaps between these two category trees can be detectd by this check. It may be useful for readers to be "warned" that they are looking at a stub article, but there is no reason why a reader (i.e. a person looking for a piece of information) would want to navigate specifically to stub articles. Editors don't need 2 ways of finding stubs on a particular topic. Stub categories cause many discussions at CFD (e.g. i n J u l y 2 0 1 4), partly because stub categories are continually adding/losing articles.
Possible way ahead:
See Wikipedia:WikiProject Stub sorting.
I suggest we change the article-side stub templates to place articles in a single category - then delete the empty categories. Note: It's also possible for editors to look at the what-links-here list for a stub template.
Another complication regarding (reader-side) stub categories is that when a category is renamed (e.g. from Category:American broadcasting to Category:Broadcasting in the United States) a subcategory for stubs (e.g. Category:United States broadcasting stubs) isn't automatically moved (by bot) to the new category (presumably because the categorization is controlled by a parameter of Template:Stub Category rather than an actual category tag).
Copied from User:Danilo.mac/Category loops in Jan 2015
List of first 200 of the 2571 category loops in Wikipedia.
In a book about World War II it would be reasonable to have a chapter titled something like "Aftermath of World War II" (including things that have a varying link to WWII) - and that might have a paragraph on the Cold War. On that basis, the Cold War might be considered a subtopic of WWII. However, similar logic would place ... ... librarian?