[Typo3] Where to change $TCA?

[Fabian Schulz]

Hello!

I finally found the right place where I can disable the 'Translate 
to'-Text. It's in TCA:

$TCA['tt_content']['columns']['header']['l10n_mode'] = 'prefixLangTitle';

But I don't get the idea where to set that value to something 
different... UserTSConfig, PageTSConfig, ... ?

Thank you,

Fabian