First, in the modern browsers I tested (FF, Chrome, and (ick) IE9) the forward-slash key is registered as a key code of 191. This surprised me because the ASCII code is 47.
Along the same lines, the question mark key is registered as 191 with a shiftKey value of true. Again, I’d have expected the ASCII code of 63.
Here’s the curve ball in the whole thing. The one really random non-conforming browser is Firefox, which registers the question mark key as a key code of 0 (zero) with a shiftKey value of true. Shame on me for thinking IE would be the oddball.