Core: Roundabout: who has priority?

On virtually every roundabout in the Netherlands, sign B6 and shark's-teeth markings at every entry arrange that traffic on the roundabout has priority over traffic that wants to enter (Book p.82). That is the rule you apply in practice almost every time. There is also a second, rare situation: a roundabout with no sign and no shark's-teeth markings at all. Then the ordinary rechts-regel applies, and here it works the other way round: traffic entering the roundabout then has priority over traffic already on it (Book p.84). The book itself calls this 'a situation you don't come across often anymore' — but rare is not the same as impossible, and the CBR exam designer knows exactly which situation candidates expect least. Separate from the priority question, the direction of travel is fixed: on a roundabout you always drive rechtsom (Book p.82).