Maybe this has been discussed before but I'm too lazy to poke around right now. It seems that a vertical foregrip in literal terms means that it is forward of the trigger and vertical to the bore. Ok, check. Well that would mean that vertical would be 90°, no? So by definition something like this (below) is not literally a vertical foregrip as it has a slight angle past 90°? Or is this another interpretive dances where you're supposed to guess at what angle it is no longer vertical?