Note: Tractor & Construction Plant Wiki:Categories is the overall category guideline page.

This page provides guidelines to choose a correct name for a Tractor Wiki category page. You have to make such choice:

  1. when you create a new category page to categorise articles and media related to a new subject on Tractor Wiki;
  2. 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;
  3. 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.

Language Edit

Category names should be generally in English (see Tractor & Construction Plant Wiki:Language policy). However there are exceptions:

  • The real policy with regard to proper names of individual persons, places, buildings, organizations etc. and other stable specific names of local phenomena is multifarious, full consensus isn't achieved yet. See current practices and discussion pages.
  • For biological taxa, the scientific Latin names should be used (see Tractor & Construction Plant Wiki:WikiProject Tree of Life). However, foods and products derived from biological sources should still use English names, for example, Category:Apples. (note few plants and aminals will require categories on Tractor Wiki as the main agricultural bias is to machinery not farming per say

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.

Grammatical number Edit

Category name that refers to type of objects or group of people should generally be in plural form: Category:Tools, Category:Artists, Category:Lakes, etc, as opposed to category referring to general theme (Category:History, Category:Weather, Category:Music) or to particular individual object (a building, a monument, an artwork, an one-shot event etc.).

Principles Edit

The Tractor Wiki categories are an organisation system for articles and media files on this Wiki. The destination of these files is the illustration (act of clarifying or explaining) of Wiki articles. So, categories are for tractor Wiki a mix of both Wikimedia Commons image libary and the articles on Wikipedia. As a result, Tractor Wiki rules regarding the naming of categories will differ from the matching Commons and Wikipedia rules:

  • Names of 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 recognise, with a reasonable minimum of ambiguity, while at the same time making categorisation of articles and media files easy and second nature. This results in popular subject categories being sub divided and having separate "xyz images" sub categories to split articles from images
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. - Most pages should have a description of the target content

Modularity principle

This principle applies to categories which combine two (or more) different criteria. We will call them “compound categories”.


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.


According to Tractor & Construction Plant Wiki: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].
Simplicity principle

This principle suggests not to combine too many different criteria. "Compound categories" combining more than three criteria tend to require too many parent categories and become difficult to manage.

Implementation of the principles Edit

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 Tractor Wiki rule
  • the Wikipedia article has been renamed

In practice, different conventions may evolved for different parts of the Wiki. Please see if there exists a category scheme or a Tractor Wiki project for your topic, and follow the conventions described there.

Categories by CRITERION Edit

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. Many criteria are currently used in Tractor Wiki, most often used are:

  • by country (nationality, its English Wikipedia variant, is deprecated in Commons)
  • country subdivision, like: by state, by county, by city, by district, etc.
  • by year
  • other time units, like: date, decade, century, etc.
  • People related

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 recommendation) 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 categorised 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 can, in some cases, be a special category as well; however it is not recommended to create categories with more than 2 criteria.

Example: Category:Politicians > Category:Politicians by office > Category:Politicians by office by country

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