A2 is the open-category subcategory "fly close to people". It is flown with C2-class drones (under 4 kg), keeping a minimum horizontal distance of 30 m from uninvolved persons. When the drone's low-speed mode is active, that distance may be reduced to 5 m.
The A1/A3 exam is no longer enough here: the pilot needs the A2 certificate of remote pilot competency. It is obtained by passing an additional exam at the CAA and confirming self-conducted practical training.