What to do and not to do while travelling to other countries

Don't do the Nazi salute: "Not even in jest. It's a crime and every year there are tourists arrested for it. Also don't carry any Nazi symbols on you." Don't wish someone a happy birthday before the actual day: "The origin is a superstition that something bad will happen to them (they might die) before their birthday if you do, however this rule is not limited to superstitious people. Even bright, rational Germans will feel uncomfortable because it's just not done."