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
Term
: a key within the taxonomy
Value
: a piece of content assigned to a term
## Example Taxonomy: Movie Website
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:
```
Actor <-Taxonomy
Bruce Willis <-Term
The Sixth Sense <-Value
Unbreakable <-Value
Moonrise Kingdom <-Value
Samuel L. Jackson <-Term
Unbreakable <-Value
The Avengers <-Value
xXx <-Value
```
From the perspective of the content, the relationships would appear differently, although the data and labels used are the same:
Without adding a single line to your [site config][config] file, Hugo will automatically create taxonomies for `tags` and `categories`. That would be the same as manually [configuring your taxonomies](#configure-taxonomies) as below:
{{<new-in"0.73.0">}} We have fixed the before confusing page kinds used for taxonomies (see the listing below) to be in line with the terms used when we talk about taxonomies. We have been careful to avoid site breakage, and you should get an ERROR in the console if you need to adjust your `disableKinds` section.
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.
### Example: Adding a custom taxonomy named "series"
{{% note %}}
While adding custom taxonomies, you need to put in the default taxonomies too, _if you want to keep them_.
{{% /note %}}
{{<code-togglecopy="false">}}
[taxonomies]
tag = "tags"
category = "categories"
series = "series"
{{</code-toggle>}}
### Example: Removing default taxonomies
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).
{{% 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.
Much like regular pages, taxonomy list [permalinks](/content-management/urls/) are configurable, but taxonomy term page permalinks are not.
{{% /note %}}
{{% warning %}}
The configuration option `preserveTaxonomyNames` was removed in Hugo 0.55.
You can now use `.Page.Title` on the relevant taxonomy node to get the original value.
{{% /warning %}}
## Add Taxonomies to Content
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/).
{{% /note %}}
### Example: Front Matter with Taxonomies
{{<code-togglecopy="false">}}
title = "Hugo: A fast and flexible static site generator"
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.
### Example: Taxonomic `weight`
{{<code-togglecopy="false">}}
title = "foo"
tags = [ "a", "b", "c" ]
tags_weight = 22
categories = ["d"]
categories_weight = 44
{{</code-toggle>}}
By using taxonomic weight, the same piece of content can appear in different positions in different taxonomies.
Currently taxonomies only support the [default `weight => date` ordering of list content](/templates/lists/#default-weight--date--linktitle--filepath). For more information, see the documentation on [taxonomy templates](/templates/taxonomy-templates/).
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:
