---
title: "Feature: #99694 - Unified Locale handling for translation files (XLF)"
manual: "TYPO3 Core Changelog"
version: "main"
permalink: "https://docs.typo3.org/permalink/changelog:feature-99694-1674552209"
source: "Changelog/12.2/Feature-99694-UnifiedLocaleHandlingForTranslationFilesXLF.rst"
typo3-version: "12.2"
typo3-major: 12
type: "feature"
issue: 99694
forge: "https://forge.typo3.org/issues/99694"
tags: ["PHP-API", "ext:core"]
rendered: "2026-09-17T21:17:42+00:00"
---

# Feature: #99694 - Unified Locale handling for translation files (XLF) {#feature-99694-unified-locale-handling-for-translation-files-xlf}

See [forge#99694](https://forge.typo3.org/issues/99694)

## Description {#description}

TYPO3 now internally uses a "locale" format following the
[IETF RFC 5646 language tag standard](https://www.rfc-editor.org/rfc/rfc5646.html).

A locale supported by TYPO3 consists of the following parts (tags and subtags):

-   ISO 639-1 / ISO 639-2 compatible language key in lowercase (such as "fr" French, or "de" for German)
-   optionally the ISO 15924 compatible language script system (4 letter, such as "Hans" as in "zh_Hans")
-   optionally the region / country code according to ISO 3166-1 standard in upper camelcase such as "AT" for Austria.

Examples for a locale string are:

-   "en" for English
-   "pt" for Portuguese
-   "da-DK" for Danish as used in Denmark
-   "de-CH" for German as used in Switzerland
-   "zh-Hans-CN" for Chinese with the simplified script as spoken in China (mainland)

A new PHP object `Locale` automatically separates each tag and subtag into
these parts.

The `\TYPO3\CMS\Core\Localization\Locale` object can now be used to instantiate a new
`\TYPO3\CMS\Core\Localization\LanguageService` object for translating labels.
Previously, TYPO3 used the `default` language key instead of the locale `en` to
identify the English language. Both are supported, but it is encouraged to use
`en-US` or `en-GB` with the region subtag to identify the chosen language more
precisely.

## Impact {#impact}

Example for using the `Locale` class for creating a `LanguageService`
object for translations:

```php
$languageService = $languageServiceFactory->create(new Locale('de-AT'));
$myTranslatedString = $languageService->sL(
    'LLL:EXT:my_extension/Resources/Private/Language/myfile.xlf:my-label'
);
```

Using this service is highly recommended, as the wrappers
`$GLOBALS['LANG']->sL()` and `$GLOBALS['TSFE']->sL()` will be
deprecated in the future.