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Reversing during driving test
If you are noticeably far from the kerb when you are reversing, then it could count as a minor. If you're just a bit far from the kerb, then the driving examiner may not even take notice of it but that depends on his/her mood really. However if you're a lot far from the kerb, like going onto the incoming lane while reversing your car, then it may be considered as a major driving fault because you're putting yourself and traffic coming in the opposite direction at risk of danger.
We have an article on minor, serious and dangerous driving faults which could be of interest to you if you want to know more.