Commons:Naming categories
From Wikimedia Commons, the free media repository
- Note: Commons:Categories is the overall category guideline page.
This page is a proposed Commons guideline, policy, or process.The proposal may still be in development, under discussion, or in the process of gathering consensus for adoption. References or links to this page should not describe it as "policy".
This page provides guidelines to choose a correct name for a Commons category page. You have to make such choice:
- when you create a new category page to categorize media related to a new subject in Commons;
- when there are several duplicate categories about the same subject, and you want to choose the correct category to gather media files and subpages in a single category page;
- when there is one or several duplicate category(ies) about a given subject, but no correct category name(s), and you want to create a new category page about an existing subject.
These guidelines match Commons:Language policy about categories, which says:
- So far, Categories are in English.
Currently, the only exception to this are categories about life forms, for which the scientific name should be used (see Commons:WikiProject Tree of Life).
Sadly, We still lack internationalization for category names, but this issue should be resolved with appropriate changes to the MediaWiki software (see bugzilla:5638). Creating intermingled category structures in different languages would only make things worse.
However, the practical details of this policy are a serious difficulty, so we must bring out some basic principles in order to implement this policy.
[edit] Principles
The Commons categories are an organization system for media files in Wikimedia Commons. The destination of these files is the illustration (act of clarifying or explaining) of Wikipedia articles. So, categories are for Wikimedia Commons what articles are for any Wikipedia. As a result, Commons rules regarding the naming of categories will differ from the matching Wikipedia rules:
- Names of Commons categories should be optimized for readers over editors; and for a general audience over specialists.
- Category naming should prefer what the majority of English speakers would most easily recognize, with a reasonable minimum of ambiguity, while at the same time making categorization of media files easy and second nature.
- Universality principle
A single name by given subject: we should not use different names to label a single subject. In particular, translations in other languages, or language variants are not an acceptable way to specify subdivisions of the main subject.
- Selectivity principle
We should not classify items which are related to different subjects in the same category. Preferably, categories should have unambiguous names. If the name is ambiguous then it is necessary to add a text to the category page in order to specify its unique subject.
- Modularity principle
This principle applies to categories which combine two (or more) different criteria. We will call them “compound categories”.
Example1:
- First criterion: to be a church (root category Category:Churches)
- Second criterion: to be located in Russia (root category Category:Russia)
The modularity principle asserts that a compound category name is made up from basic names (matching the criteria), which are put together according to a fixed form. These forms are specified in general rules or schemes.
Example2:
- According to Commons:By location category scheme, the pattern, for the category name which matches example 1, is: “[object] in [location name]”.
- Therefore, the category name will be Category:[Churches] in [Russia].
[edit] Implementation of the principles
We have to realize that Commons Wikimedia project is not a Wikipedia project, and that we have limited competences regarding Encyclopedic matter. Therefore, we should not repeat debates, in Commons, about issues which have been resolved after hard word and sustained discussions in a Wikipedia project.
Which project? Inevitably due to the language policy rule, the English Wikipedia will be the reference for any encyclopedic issue, there is little choice but to use matching English Wikipedia articles as the basis for Commons category names.
However, there are several exceptions where the English Wikipedia article name would not be used:
- the Wikipedia article name would not appropriately identify the subject of the category. That is the case, in particular, when the subject of the Commons category does not exactly match the subject of the Wikipedia article example?
- the Wikipedia article name does not comply with the Wikipedia naming conventions
- the Wikipedia article name is excessively verbose
- the Wikipedia article name does not comply with a specific Commons rule
- the Wikipedia article has been renamed (In Commons, we don't move a category each time a matching Wikipedia article is renamed)
In practice, different conventions may have evolved for different parts of Wikimedia Commons. Please see if there exists a category scheme or a commons project for your topic, and follow the conventions described there.
[edit] Categories by CRITERION
These are special categories which are useful to group other related pages (not media files) according to a given criterion. They hold only other categories and should be marked with {{MetaCat}} template.
You can choose any appropriate criterion. These criteria are currently used in Commons:
- area
- color
- continent
- country (nationality, its English Wikipedia variant, is deprecated in Commons)
- country subdivision, like: states, counties, cities, districts, etc.
- culture
- date (example: Category:Warsaw Uprising photos by date)
- ethnic group
- genre
- occupation
- office
- period
- photographer
- region
- season
- subject
- year (see examples in Category:Categories by year )
For a given criterion, you must associate a set (often a finite set) where you'll pick elements to build the names of the subcategories.
Example: Assume (it's not a recommandation) you want to group pictures, which are Category:Spheres, showing spheres of a given color. The associated set is an indefinite list of colors, like red, yellow, green, crimson, periwinkle blue, and so on. The matching categories would be:
- Category:Red spheres
- Category:Yellow spheres
- Category:Green spheres
- Category:Crimson spheres
- Category:Periwinkle blue spheres
and they'd be categorized in Category:Spheres by color.
Notice that you must not put a category like Category:Wooden spheres in this group, because wood is a material, not a color (you can find natural wood of different colors, and also cover it to change its natural color).
So, normally, the name of the special category is built as follows:
-
- PARENT CATEGORY by CRITERION
PARENT CATEGORY can be a special category as well.
Example: Category:Politicians > Category:Politicians by office > Category:Politicians by office by country
- Category:Politicians by office by country ends with “by country”, therefore, you know that the criterion is the country. So, you may expect to find categories of various countries in this category.
- According to the rule above, a correct subcategory is Category:Politicians of Canada by office, and not Category:Politicians by office of Canada, because:
- You can also apply the rule at this level: Category:Politicians of Canada > Category:Politicians of Canada by office
- “office of Canada” is an ambiguous expression, and may be interpreted to be itself the criterion.
