Explanation: A tachograph allows you to select the mode or task that you're undertaking. Time spent on that task is then recorded automatically. Each task has a different symbol. You need to know the meaning of each, so that your records are correct. The modes are: driving, doing other work, on duty and available for work, and taking a break or rest.
Category: Drivers' Hours and Rest Periods
References: The Official DVSA Guide to Driving Buses and Coaches: Section 3, The Official DVSA Guide to Driving Goods Vehicles: Section 3