When using this term "ticket" what I/we are saying, is that the person has attended a training course & passed a test, so can demonstrate a level of competency surrounding the Building Regulations Part G (3) which includes vented, un-vented, control of water temperatures to baths etc, etc.
Without this ability to demonstrate competency you could
not join a Competent Persons Scheme & therefore self notify any installation or alterations required under Part G (or any of the others).
You could also
not include details (card number) on the Building Notice that your customer will have to submit if you are not a member of a CPS. The work you carried out for them may also not comply with the requirements Reg's as you have not kept up with the changes in the Law.
That's why we need to have CPD as professional engineers, IMHO that is the real purpose of the course.
Sorry Mike but as vented cylinders are now included in G3 they are notifiable as a new installation & as a controlled service & as an appliance that can be commissioned (hence that they have bentchmark cert's on them now) & I am sure there are many more !! (vented cylinders may have to be fitted with any of the items found on un-vented one's e.g. T&P, overheat stats, so the lines are now blurred between them.
"There is no requirement in Part G for anyone installing open vented systems to be part of a competent persons scheme.
The regs only mention the need for a person to be a member of a competent persons scheme in relation to unvented systems."
Of course, wether anybody actually does this is quite a different matter.