I'm puzzled by which machines are covered by these regulations, and which aren't. I bought a new farm telehandler three or four years ago, and a dairy farmer f

I'm puzzled by which machines are covered by these regulations, and which aren't. I bought a new farm telehandler three or four years ago, and a dairy farmer friend did about the same time. His machine has the reversing alarm which is apparently non-optional. Mine doesn't, and as far as I know, they never sell anything with one. They're from different manufacturers and mine's centre-pivot whereas his is side-mount, but they're basically similar-sized kit to do the same job. Nonetheless, only one of us makes an enemy of the neighbours at 4am. (I wonder if the rules only require them for construction sites, and my manufacturer doesn't sell into that market whereas his does?)