Real quick, some different rules between HS and club (FIFA). Many parents are more familiar with FIFA rules.
In HS......
1. If you get 2 yellows you can be replaced.
2. If a throw-in "never came in", it goes to the other team.
3. You can sub on your own corner kick, providing you are already at the half field line.
4. Once you put a ball down for a goal kick, you can't move it to the other side.
That's a few that I've seen "confuse" some parents in the stands.
Coach P......feel free to add a couple more.