[unwind]

Since we're kind of talking about things from an I18N perspective, those characters are written like this on a bog standard Swedish keyboard:

    \ is AltGr+?
    ] is AltGr+9
    ^ is Shift+^, then space
    _ is Shift+-

AltGr is the right Alt key, to the right of the space bar.

So none of those are single keys, which means that combining them with Ctrl to write control characters becomes almost comically difficult. Not very accessible to typical users, I'd say.

[unwind]

Actually \ is AltGr++, i.e. "+" is the symbol you get from that key without any modifier. With shift you get ? and with AltGr you get \. My bad, and too late to edit.