I've done some digging around old forum posts, but can't quite find the answer to what I'm trying to do. To try to make passwords a bit more unguessable, instead of using a current scheme of including one punctuation character for our sales force, another for our design team, another for execs and so on, I'd like to include a more random element. But what characters can I NOT use? I'm looking at all possible options on a standard US keyboard, which would mean these characters:
Which do I need to avoid?