A "DRL" switch, or a "DRL" position on the light switch? Where have you seen that?

Yes, I admit that the 'off' position of the lights is virtually "DRL" when you turn on the engine, in that the low beam headlights will turn on (even though the high beams won't stay on, but only allow flashing), but only while the engine is on. But even if you turn the switch to "headlights" (in which case your can have your high beams work), the headlights will still turn off when you turn off the engine (at least, that's the case in all the cars Volvos I've owned from model year '93 to 2007). The only way you can leave any lights on with the engine off is by turning the light switch to "parking" lights.