I've never even heard of a minimum bend radius, and I care about my kit so I do tend to read the docs that come with it. Where are such details given, because I'm now curious, thanks.
I don't know about all cables, but Cat 6 has a generally accepted minimum radius of 4 times cable width and there's some standards to back that up.
You can also find datasheets for industrial cable that specify it for fixed installations and repeated flex applications: https://www.sab-kablo.com/fileadmin/user_upload/pdf/catalog_... (notably this has 5 times the diameter, so it wouldn't pass some standards)
Consumer cables, not just Ethernet, probably do have such specifications when produced in bulk, but the manufacturer that turns reels of 1000 metres of raw cable might not include it in the end manual (just like they usually don't include the frequency response curves in there).
