How do you manage multiple domains under a ccTLD?

[Stephane Bortzmeyer]

On Fri, Nov 01, 2024 at 10:16:42AM +0000,
 me aharen <aharen at outlook.com> wrote 
 a message of 110 lines which said:

> I am interested to learn how ccTLD operators handle zone file
> management.

It depends on the TLD. .com certainly does not work like .bf or
.fr. Big TLD typically don't use zone files anymore, they are too long
to sign and load.

> For example, I am the owner of .IO ccTLD and I would like to manage
> this domain. Do I only create a single zone file .io and all the
> entries to that file? Or do I need to to create a zone file for each
> domain that gets added to the list. Ex, a customer bought the domain
> hello.io, ministry.gov.io etc.

If the domain example.io is delegated, the manager of .io just adds
the hint for the delegation:

example  IN  NS ns1.something.net
         IN  NS ns1.otherthing.net

And may be glue and DNSSEC information. Everything else is in the
child zone (example.io), managed by someone else.

The typical TLD is delegation-only so, except for a few records at the
apex (NS, SOA, DNSKEY, may be a TXT), they contain only delegations
like the above one.