Is <Ctrl>+Y hardcoded?

Hi all!

I have these keybindings defined in .trinity/share/config/kdeglobals:

[Shortcuts] Redo=Ctrl+Shift+Z Undo=Ctrl+Z

And I have these keybindings defined in .trinity/share/config/katerc:

[Katepart Shortcuts] backspace=Backspace;Shift+Backspace delete_line=Ctrl+Y

So I assume, <Ctrl>+Y deletes a line in kate. But it doesn't, it perfoms "Undo" instead. This only affects TDE applictions (kmail, kwrite, kate ...) but all others are unaffeted. For example "geany" behaves is configured the same way (<Ctrl>+Z = undo, <Ctrl>+Y = delete line)

There is no match for "Ctrl+Y" neither in /etc/trinity nor /opt/trinity/etc/.

So ... did I miss something? Or is "Ctrl+Y" hardcoded somewhere to be "Undo"?

Nik