Today, I found an example of anarchaic law. In spite of the absence of regulation on journalism in certain countries, they still follow unspoken rules, such as avoiding private matters.
Please post examples where people follow certain rules, in spite of the fact that they can voluntarily choose to not follow them at any time without punishment from the state, that are followed in spite of the absence of government legislation.
A good example is kosher certification. Private agencies (hechsherim) inspect and regulate kosher food to standards over and above the government’s, and consumers know what certification marks to look for.
So if someone thinks that the government is necessary to monitor food safety, you can say: A private solution already exists for kosher food, and the people who care about food being kosher are vastly outnumbered by those who care about food being healthy. Therefore, there is every reason to expect that private regulatory agencies can take the place of government food inspection.
I’m not sure if this qualifies, but UL (underwriters laboratories) checks all sorts of products (apparently everything from electronics to body armor) for safety. UL is a private company, and they get paid by companies they inspect.
Computers are heavily standardized. DDR[123], PCI(e), [PS]ATA, etc were all designed by private industry bodies. Not sure about ISO.