TYPO3 Core

In powermail we need a possibility to set a field value for field marker.
I want to have the value in default language but an empty value for translation.

So documenation to l10n_mode (see https://docs.typo3.org/typo3cms/TCAReference/Reference/Columns/Index.html#l10n-mode) says for value exclude:

... Excluded fields will not be copied when a language-copy is made. May have frontend implications.

If I localize a field in powermail, the value is still copied to the localized record.

I created a very simple extension, to attach to this ticket to give you a quick example.
Just localize a record and you will see that the value of the field with l10n_mode=exclude is also copied.
In TYPO3 7.6 the value was empty in the localization.