Traffic signs that give orders are generally circular in shape. Most of these circular signs have a red border and are prohibitory, meaning they indicate what drivers must not do, such as speed limits or no-entry signs. There are also blue circular signs that give mandatory instructions, telling drivers what they must do, like keep left or turn ahead only. Additionally, the "stop" sign is an exception with an octagonal shape to make it stand out, and the "give way" sign is triangular with a red border. Overall, circular signs with red or blue backgrounds dominate the category of traffic signs giving orders.