description: Hugo includes support for user-defined taxonomies to help you demonstrate logical relationships between content for the end users of your website.
Hugo includes support for user-defined groupings of content called **taxonomies**. Taxonomies are classifications of logical relationships between content.
### Definitions
Taxonomy
: a categorization that can be used to classify content
Let's assume you are making a website about movies. You may want to include the following taxonomies:
* Actors
* Directors
* Studios
* Genre
* Year
* Awards
Then, in each of the movies, you would specify terms for each of these taxonomies (i.e., in the [front matter][] of each of your movie content files). From these terms, Hugo would automatically create pages for each Actor, Director, Studio, Genre, Year, and Award, with each listing all of the Movies that matched that specific Actor, Director, Studio, Genre, Year, and Award.
### Movie Taxonomy Organization
To continue with the example of a movie site, the following demonstrates content relationships from the perspective of the taxonomy:
Without adding a single line to your [site config][config] file, Hugo will automatically create taxonomies for `tags` and `categories`. That would be same as manually [configuring your taxonomies](#configuring-taxonomies) as below:
When taxonomies are used---and [taxonomy templates][] are provided---Hugo will automatically create both a page listing all the taxonomy's terms and individual pages with lists of content associated with each term. For example, a `categories` taxonomy declared in your configuration and used in your content front matter will create the following pages:
* A single page at `example.com/categories/` that lists all the [terms within the taxonomy][]
* [Individual taxonomy list pages][taxonomy templates] (e.g., `/categories/development/`) for each of the terms that shows a listing of all pages marked as part of that taxonomy within any content file's [front matter][]
Custom taxonomies other than the [defaults](#default-taxonomies) must be defined in your [site config][config] before they can be used throughout the site. You need to provide both the plural and singular labels for each taxonomy. For example, `singular key = "plural value"` for TOML and `singular key: "plural value"` for YAML.
If you want to have just the default `tags` taxonomy, and remove the `categories` taxonomy for your site, you can do so by modifying the `taxonomies` value in your [site config][config].
{{<code-togglecopy="false">}}
[taxonomies]
tag = "tags"
{{</code-toggle>}}
If you want to disable all taxonomies altogether, see the use of `disableKinds` in [Hugo Taxonomy Defaults](#default-taxonomies).
Therefore, if you want to have a taxonomy term with special characters such as `Gérard Depardieu` instead of `Gerard Depardieu`, set the value for `preserveTaxonomyNames` to `true` in your [site config][config]. Hugo will then preserve special characters in taxonomy values but will still normalize them in URLs.
Note that if you use `preserveTaxonomyNames` and intend to manually construct URLs to the archive pages, you will need to pass the taxonomy values through the [`urlize` template function][].
{{% note %}}
You can add content and front matter to your taxonomy list and taxonomy terms pages. See [Content Organization](/content-management/organization/) for more information on how to add an `_index.md` for this purpose.
Before 0.49, Hugo would make the first character upper case for the taxonomy values for titles even if `preserveTaxonomyNames` was active. This no longer the case, which (for instance) makes it possible to have fully lower-case values.
Once a taxonomy is defined at the site level, any piece of content can be assigned to it, regardless of [content type][] or [content section][].
Assigning content to a taxonomy is done in the [front matter][]. Simply create a variable with the *plural* name of the taxonomy and assign all terms you want to apply to the instance of the content type.
{{% note %}}
If you would like the ability to quickly generate content files with preconfigured taxonomies or terms, read the docs on [Hugo archetypes](/content-management/archetypes/).
A content file can assign weight for each of its associate taxonomies. Taxonomic weight can be used for sorting or ordering content in [taxonomy list templates][] and is declared in a content file's [front matter][]. The convention for declaring taxonomic weight is `taxonomyname_weight`.
The following TOML and YAML examples show a piece of content that has a weight of 22, which can be used for ordering purposes when rendering the pages assigned to the "a", "b" and "c" values of the `tags` taxonomy. It has also been assigned the weight of 44 when rendering the "d" category page.
By using taxonomic weight, the same piece of content can appear in different positions in different taxonomies.
{{% note "Limits to Ordering Taxonomies" %}}
Currently taxonomies only support the [default `weight => date` ordering of list content](/templates/lists/#default-weight-date). For more information, see the documentation on [taxonomy templates](/templates/taxonomy-templates/).
{{% /note %}}
## Add custom metadata to a Taxonomy Term
If you need to add custom metadata to your taxonomy terms, you will need to create a page for that term at `/content/<TAXONOMY>/<TERM>/_index.md` and add your metadata in it's front matter. Continuing with our 'Actors' example, let's say you want to add a wikipedia page link to each actor. Your terms pages would be something like this:
You can later use your custom metadata as shown in the [Taxonomy Terms Templates documentation](/templates/taxonomy-templates/#displaying-custom-metadata-in-taxonomy-terms-templates).
