I'm not sure if this is something you can actually do anything about, but maybe a note in the docs might save someone else the trouble of debugging the situation I just uncovered.

I wanted to bind the bar ( |) character to flip horizontal. In order to actually type that character, I hold down <Shift+backslash>. However, in my imv config, the bind has to be defined as <Shift+bar> in order to work. <Shift+backslash> does not work, but <backslash> does work. Ideally, <bar> should be enough to use as a bind key, but if it's not possible to bind to just bar, perhaps a note in the docs explaining the nuance is needed.