Thank you Tam for putting it better than I have been managing to do!
Reza - I support what you are trying to do, but I think you have become seriously obsessed with GSR being the only true measure of competence. The "one ring" of gas work if you like. It proves very very little in reality.
The instructor on my course is an example. He is in his 60s, came up through the Gas Board as an apprentice, then gas engineer, supervisor, manager, trainer and finally to a private provider. He had retired off the tools and let his registration lapse. In your book, he is not competent to work on gas! I would never be so arrogant or blind to his decades of experience and knowledge as to dismiss someone like that. I'd rather have him fit my boiler than a lot of the guys that I went through the course with. They were great at memorising what's in the books, and at passing exams, hopeless on the tools. I include myself in that, by the way. I knew very little when I qualified, and most of what I've learnt has been since that time, through experience. Yet if I let my registration lapse, by your reckoning I would be less competent now, than I was was I first got my GSR number!
Remember also that registration only became a legal requirement in 1998 with the introduction of GSIUR. Before that there was no registration scheme, no exams or assessments. Are you suggesting that everybody working on gas before that time was incompetent?
I think you are placing far too much importance on a piece of paper and a little plastic card. Knowledge, skill and experience don't just come from passing exams, and there are people out there who have never taken ACS who are far better engineers than you or I will ever be.