If for any reason you can't make an event that you have said you will be going to, then please let one of your section Leaders know as early as possible. This will allow them to make any alternative arrangements, particularly for District events where teams are needed. Your Leaders (and Leaders from other Groups) voluntarily give up a great deal of their precious spare time to run these activities for you, and it is not fair that they should be inconvenienced by people not turning up.