I was waiting for that one!OK, what if I say 'masonry nail'.
The point surely is that no form of barrier will mechanically protect a cable against a 'material-appropriate' attempt to attach a fixing - e.g. even if it were 1" thick steel, someone might drill into it for an attachment - so what (if anything) do you believe would satisfy 522.6.101(iv)?
Kind Regards, John.