On Thu, 15 Mar 2018, Tony Finch wrote:
As I understand it, the old hosts.txt registrations got grandfathered into the DNS in the .arpa zone - they were ARPANET hosts (e.g. see RFC 921). The modern structure was set up after the transition to IP, so it's fair to call .com and friends Internet domains. (See RFC 920.)
Yeah, I was referring to DNS as opposed to HOSTS.TXT of course.
But it looks like there were a bunch of .edu and .gov names before Symbolics.
I'm happy to be corrected/updated; I happen to have an interest in geeky history (as if that wasn't apparent).