At larger orienteering events (Badge events and upwards) the information about controls is provided in a standard pictorial format - a sort of Esperanto for orienteering. Control description sheets are displayed in the assembly area and the orienteers can view them. Even among experienced orienteers comments along the lines of 'what does that symbol for control 7 mean again' can be heard: so if they are having problems the pictorial descriptions can be particularly daunting to newcomers to such events.
For a more friendly guide on pictorial descriptions check out MapRunner.co.uk's guidance: