Comment 37 for bug 1357895

So, at first I thought this wasn't possible because of the way gnome-settings-daemon handles shortcuts. Then I remembered that we are actually using Mutter's keybinding handling now, so I went to look at the code and see if it could be possible. If my understanding of the code is right, any keybinding that does not have a keysym (something that is not between <>) will be ignored and will actually do nothing, and that's the case for the examples you say.

I've been looking a lot onto this, but I can't seem to find any implementation of keybindings that doesn't require an alphanumeric character but it seems there isn't. The only place I know these were used was on xkb, and many people got used to them, but for now I don't see a way in which this could be done.

Now, did setting the next-input-source to '<Shift><Ctrl>' made unusable your browser's keybindings? because I tried and that didn't happen, also I think Mutter should just ignore it so nothing should change.