The braid if used on low voltage cabling must be earthed, consider a conductive object pierces the cable into the phase only, it would make the whole of the braiding live, where the regs state it should not be used as a power cable it refers to using it as tails but since the latest amendment it is no longer recognised to meet BS standards for general use, if anyone users this stuff and does not earth the braid and yet they class themselves as competent then they really want to question their knowledge.. its a braid or a screen and can be used for low voltage but you have to know when and why it can before you do, the numpties that tell you it's ok without earthing of the braid are questionable about their competence to be electricians considering it can kill if not earthed.