[TYPO3-english] TCA override accessible only for specific ext.

[Arno Dudek]

Hi!

If you have news installed, you can look there how they do it with the 
field "showinpreview". Look in the files
news/Configuration/TCA/Overrides/sys_file_reference.php
and
news/Configuration/TCA/tx_news_domain_model_news.php (line 722 ff.)

lg arno