# How can I find out where a key binding is coming from?

In previous versions of Mathematica, I could add these lines to my KeyTranslations.tr file, to map Ctrl+[ to [[:

Item[KeyEvent["8", Modifiers -> {Control}],
FrontEndExecute[{
FrontEndNotebookWrite[FrontEndInputNotebook[],
"\[LeftDoubleBracket]", After]
}]],
Item[KeyEvent["9", Modifiers -> {Control}],
FrontEndExecute[{
FrontEndNotebookWrite[FrontEndInputNotebook[],
"\[RightDoubleBracket]", After]
}]],


(I had to modify @rmrf's original key binding, because there are no [ and ] keys on a German keyboard. They're under the 8 and 9 keys, so I mapped those. I also had to comment out the other occurrence of KeyEvent["9", Modifiers -> {Control}, in the same file.)

In Mathematica 10, this works for Ctrl+8, but not for Ctrl+9, so I'm guessing Ctrl+9 is bound to something else.

Is there a way to find out where Ctrl+9 is mapped (so I can change it there)? It's not listed under tutorial/KeyboardShortcutListing, and I couldn't find it by grep'ing for KeyEvent["9" in the SystemFiles folder

• This doesn't answer your more general question, but Ctrl+9 inserts an inline cell within a cell of compatible style (e.g., Text). – mfvonh Jul 12 '14 at 12:11
• @mfvonh: I just realized that my question was only half true: I did find another KeyEvent["9", in the same file, mapped to CreateInlineCell. I commented that out already - but it still seems to be active. Sadly, these EventTranslations seem to be completely undocumented. – Niki Estner Jul 12 '14 at 12:18

@mfvonh's comment told me where to look: Apparently, the MenuKey in MenuSetup.tr also binds a key to a command. So Ctrl+9 was bound twice, in KeyTranslations.tr and again in MenuSetup.tr. Once I removed/changed both bindings, I could re-bind Ctrl+9 to ]].