---
title: "Feature: #79658 - Synchronized field values in localized records"
manual: "TYPO3 Core Changelog"
version: "main"
permalink: "https://docs.typo3.org/permalink/changelog:feature-79658"
source: "Changelog/8.6/Feature-79658-SynchronizedFieldValuesInLocalizedRecords.rst"
typo3-version: "8.6"
typo3-major: 8
type: "feature"
issue: 79658
forge: "https://forge.typo3.org/issues/79658"
tags: ["Backend", "Database", "Frontend", "PHP-API", "TCA"]
rendered: "2026-09-20T18:31:11+00:00"
---

# Feature: #79658 - Synchronized field values in localized records {#feature-79658}

See [forge#79658](https://forge.typo3.org/issues/79658)

## Description {#description}

The localized record overlay behaviour has been changed to make localization-rows standalone.

Previously, if fields in `TCA` columns were set to `l10n_mode` `exclude`
or `mergeIfNotBlank`, the localized record overlay did not contain values, and those
values were "pulled up" from the underlying default language records.

This has been changed, the `DataHandler` now copies those values over to the localized
record and synchronizes them if the default language record is changed.

As a substitution of the `mergeIfNotBlank` feature, the new configuration `allowLanguageSynchronization`
has been added. Setting this adds a wizard to single fields and an editor can select if a field of a localized record
should be kept in sync with the default language record, or the localized record it was derived from.

A typical configuration looks like that:

```php
'columns' => [
    ...
    'header' => [
        'label' => 'My header',
        'config' => [
            'type' => 'input',
            'behaviour' => [
                'allowLanguageSynchronization' => true,
            ],
        ],
    ],
],
```

`TCA` tables that configure the language localization get the field `l10n_state` added by the schema analyzer
which stores a json string with field names and the values `custom`, `parent` or `source` to
specify if and from which record a single field gets its value.