Well I found this while searching the same thing. My 17 year old son has just started driving lessons. Once he passed his cbt I sent his licence off to have this added to his provisional licence. I don’t know why I did but I read something somewhere which said it was worth doing. Well it’s come back with cat A from his 17th birthday. Now, knowing the rules as I do, I know this can’t or at least shouldn’t be right. I’ve checked with his dad who is a driving instructor and examiner and a full uk bike licence holder. Sure enough his full licence and my sons provisional both have the same. When I check online, his shows cat A for motorbikes and has the exact wording you’ve written above?? I know it must be a mistake as he’s only done his cbt and by my understanding of the rules he was restricted to a 50cc untill he was 17 and then could ride up to a 125cc. I am sooooo confused