> ## Documentation Index
> Fetch the complete documentation index at: https://developers.deepl.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Customize

> Tailor DeepL translations to your domain with glossaries, style rules, custom instructions, and translation memories.

DeepL's customization features let you control terminology, style, and consistency across your translations. They complement each other, and you can combine them in a single request:

| Feature                                                            | What it controls                                                                     | How it's applied                                                             |
| :----------------------------------------------------------------- | :----------------------------------------------------------------------------------- | :--------------------------------------------------------------------------- |
| [Glossaries](/docs/customize/managing-glossaries)                  | Exact translations for specific terms, like product names or industry vocabulary     | Stored on your account; passed per request via `glossary_id`                 |
| [Style rules](/docs/customize/using-style-rules)                   | Formatting conventions (dates, numbers, punctuation) plus stored custom instructions | Stored on your account; passed per request via `style_id`                    |
| [Custom instructions](/docs/customize/custom-instructions)         | Tone, phrasing, and domain-specific behavior via natural-language directives         | Inline per request via `custom_instructions`, or stored in a style rule list |
| [Translation memories](/docs/customize/using-translation-memories) | Reuse of your previously approved translations for matching segments                 | Stored on your account; passed per request via `translation_memory_id`       |

All of these work with both [text translation](/docs/translate/translate-text-quickstart) and [document translation](/docs/translate/translate-documents-quickstart), and with all `model_type` values.

<Warning>
  Glossaries and style rules are unique to each of DeepL's global data centers and are not shared between them. Clients using [regional endpoints](/docs/getting-started/regional-endpoints) can't access glossaries or style rules created in the UI at this time.
</Warning>

## Start here

<CardGroup cols={2}>
  <Card title="Glossaries in the Real World" icon="book-open" href="/docs/customize/glossaries-in-the-real-world">
    A hands-on tutorial: build a glossary and apply it to keep customer-facing terminology consistent.
  </Card>

  <Card title="Managing Glossaries" icon="list-check" href="/docs/customize/managing-glossaries">
    Create, edit, retrieve, and delete glossaries with the v3 endpoints, and use them in translations.
  </Card>

  <Card title="Using Style Rules" icon="pen-ruler" href="/docs/customize/using-style-rules">
    Build style rule lists with configured rules and custom instructions, and apply them via style\_id.
  </Card>

  <Card title="Custom Instructions" icon="wand-magic-sparkles" href="/docs/customize/custom-instructions">
    Best practices for writing natural-language instructions that produce consistent results.
  </Card>

  <Card title="Using Translation Memories" icon="database" href="/docs/customize/using-translation-memories">
    Retrieve your translation memories and control the matching threshold in translation requests.
  </Card>

  <Card title="Customizations for Language Variants" icon="globe" href="/docs/customize/customizations-for-variants">
    Create customizations with root language codes and apply them to variants like pt-BR or fr-CA.
  </Card>
</CardGroup>

## API reference

Glossaries, style rules, and translation memories each have management endpoints under the [API Reference](/api-reference/multilingual-glossaries/create-a-glossary). If you're still on the deprecated v2 glossary endpoints, see [Glossary v2 vs v3 Endpoints](/docs/customize/glossary-v2-vs-v3-endpoints) for the differences and migration considerations.