Comment by OJFord

Yes, because you have to be (or be about to be and in time to start) a doctor in order to be apply for residency.

Resident doctors are doctors, exactly as junior SWEs are software engineers.

(UK doctors have for some reason long objected to 'junior' and recently become 'resident doctors' over exactly this. All the more confusing - throughout and still there's been 'Senior House Officers', because 'house' used to be what it was called, like US residency, doing house, there were junior and senior house officers, so why not just revert to that? Who knows, but now they're all resident doctors - and some of which are senior house officers - until they're registrars/consultants, and they're happier with that than junior doctors.)