Young children can learn this implicitly through a wide variety of activities in which they are looking for orienteering flags. The flags do not necessarily need to be on a course and do not need to have traditional electronic (SI) punches or manual pin punches at them. They can have bingo stamps, stickers, or nothing at all. They also do not necessarily need to have traditional (or any) control codes when working with particularly young children.
No relevant resources have been linked to the skill or practice "Learn what we are looking for (i.e. control flags)".