Bust cards are often used to contain basic advice on what to do if arrested, and to give people the number of a defence lawyer experienced in protest related cases.
They can also be useful though, to get other key messages across – such as what to do if you are stopped and searched, or your rights in relation to police photography.
It is up to you how you want to use your bust card, and what information you want to put on it. The general rule is the simpler the better but keep in mind who it is you are trying to reach. Make sure the information you are putting across is relevant to the people who will be on the demonstration.