The keyboard settings window has a "Application Shortcuts" tab with a keybinding indicated as "c"; However the same window also has a "Close" button, with an keybinding indicated as "C". This has the unfortunate consequence that someone who is not using a pointing device and tries to navigate to the tab using the marked acclelerator, will close the window instead. I marked this trivial because one can still navigate to the tab using the keyboard by pressing tab untilone navigates to the tab bar, and then press the right arrow. Still, it should be fixed, and should be trivial to do so.
Thank you for your bug report. This is fixed in the git master branch (commit e8098c2275bf9a48e4f57b5b496f812017899813).