Martin,
WELCOME TO THE AWS WELDING FORUM!!
I'm with PWC, we really need a little more info here.
But, off hand, I would venture that you are working to D1.6 even if it is generally under D1.1. Once you go to a stainless you are going to have to utilize both if I remember correctly.
Now, your job specs/contract documents are probably going to give you some of your answers. As will the type of joint, type of job, and other considerations.
More than likely you will find this definitely has to be qualified by testing which means the first welder is qualified by testing and then testing procedures are set up upon successful qualification of the procedure and establishment of a WPS.
NDT will be a combination of joint details with applicable code and contract documents.
Have a Great Day, Brent