ajaxorg/ace — comment on commit b47e26e8a993616ab5d2e9da1e17e9a0e21bab5f
File: lib/ace/lib/keys.js line 104
By nightwing:

keycodes vary in layouts
but for keybindings including `ctrl|alt` or for vim main mode one doesn't care about layout (`ctrl+c` must work even if language have no `c` at all)

`'` is just for consistency since all others are lower characters on qwerty layout