Volvo 2007 S80 Owner's Manual page 78

Parking lights
The front and rear parking lights can be turned on even when the ignition is switched off.
Turn the headlight control to the center position (the license plate lighting comes on at the same time).
The lighting also comes on when the trunk lid is opened in order to alert anyone traveling behind your vehicle.
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03 Your driving environment
Lighting
Brake lights
The brake lights come on automatically when the brakes are applied.
Emergency brake light (EBL)
Emergency Brake Lights, EBL are activated in the event of sudden braking or if the ABS brakes are activated. This
function causes the brake lights to glow more intensely to alert vehicles traveling behind.
The system is activated if ABS is used for more than approximately a half second or in the event of sudden braking,
although only at speeds above approximately 6 mph (10 km/h).
When the vehicle stops, the brake lights and other taillights remain on and glow brighter than normal for as long as the
brake pedal is depressed or until braking force on the vehicle is reduced.
Front fog lights
The front fog lights can be switched on together with high/low beams or the parking lights.