I’ve got the book.
They have also deemed pvc cables concealed in walls a C2 without additional protection via 30mA rcd, mechanical protection etc.
I’ve got the 17th edition version 1 book also given to us in a tool box talk ,where in that version cables concealed in walls etc ,is given what I would say as the industry collective opinion of a C3.
Don’t know if they have changed their minds or it’s a mistake in the publication?
It’s decent but as the inspector the codes are yours to put down and no one else’s in my opinion.
There’s loads of codes in the book I feel are not what I would code.