On Mon, 13 Dec 2021 19:19:47 +0800 Frank Hwa <fr...@tomatoservers.com> wrote:
> for the second level domain, some are "com.au", "com.hk" (the com > one), some are "co.uk", "co.jp" (the co one). I am not sure, isn't > there a standard for this naming? > A long-standing convention to use ISO 2-letter country codes as TLD for each nation since at least the beginning of DNS, IIRC. For consistency sake, 2 letter 2nd level domains were used. ie, co, or, ac (equivalent of edu), etc. The US had and still has the .us. TLD. but that uses a different policy than the rest of the world. These may be codified, most likely are. I have had no reason to look into it. The most common TLDs of org, com, net, edu, mil, etc., are persistent artifacts of ARPANET. These are codified in early RFCs. -- --
