I try to change some *.dtl files without adding a new theme. so I coppied them from $otrsho/Kernel/Output/HTML/Standard to $otrshome/Custom/Kernel/Output/HTML/Standard and changed them.
From the README file in the Custom directory I understood, that files inside that directory will be loaded instead of the default files. Is that correct?
To keep it short it didn't work for me.

Do I need to activate the feature of that Custom directory?