That made me laugh. You think to get a commercial airline license that you go on-line and apply? What is all this .co.uk business? The caa is the civil aviation authority. They have a website as google has told you, but its not for doing exams on. When you do the exams you go to a designated exam hall. Where you sit, and an invigilator makes sure you are who you say you are checking your ID, that you don't cheat and that the exam conditions are adhered to. I should also point out I went to a professional training college. I didn't just turn up and do an exam. 
As for whether I fly or not, I guess you'll need to lurk moar to find out.
Actually to be honest with you yes someone applies online initially to sit and take the exams at the 'caa.co.uk' exam centre but you already know that since you sat the exams and got your licence:) but you cannot witness it ::)but you ask witnessing from others! aka me!
.co.uk refers to the UK caa, the country you live in.
Yet though if you have sat the exams it would be easier for you to post for example 'I should point out when i sat my exams for my commercial pilots licence i didn't just turn up and do(you should have said 'sat my exams') an exam.
Still you brought up a driving test and a professional training college on your reply's above, were it would have been more relevant to refer to a flight test and commercial pilots exams and easier and on the subject of flight but you didn't because its not the first thing you can think of because you are simply not trained in to it and is obvious.
You know there is a jargon amongst pilots and student pilots and it is something you haven't used here because simply you are not aware of it and believe me you cannot google it, you have to be involved, which you clearly not, despite your claims!
as if i would try to engage in a conversation with baristers for example or biologists claiming I am one, i would make fool of my self to them cos i don't have knowledge of their specialities at the deep level they do and the jargon they use.
Not only young people use the internet these days and not all of them who post here are outside the circles and professions they 'claim' but you are aware of that young man and you don't really believe in a flat earth, you are just in here for the fuss of it
as most of you.
Well I will forgive your naiveness no offence, actually i believe you are a brilliant young man.
P.S. its not commercial airline pilots licence Its ATPL but you already know that
And its not INS its IRS (ISU) inertial reference system that is being used for more than 30 years and the only errors it has is those the pilot might accidentally type in.
Actually it was back in 1973 and the first platform to incorporate such system was the F-16 fighting falcon.