Except that IN's and GM's are published to inform and provide guidance. These notices or the guidance do not form part of the legislative text.
Sadly I agree with those who believe that the CAA has lost the plot, and I am sure that many would describe it as an authority that is fast becoming unfit for purpose.
It took the Shoreham accident to focus a very bright light on the CAA's oversight of airshows. I hope that they get to grips with overseeing this matter before an innocent prospective student comes to grief while receiving a trial lesson from a 100hr PPL dressed in three cornered trousers!