ds

.citadel

Generic top-level domain

RDAP + WHOISbrand TLD

Nobody outside the registry can register here. .citadel is a brand TLD run by Citadel Domain LLC, which under ICANN's Specification 13 means its operator is the only permitted registrant. ds reports names here as PRIVATE rather than AVAILABLE, and leaves the zone out of --tld all unless you pass --private include. See Brand and reserved TLDs.

Registration
Closedno public names
Operator
Citadel Domain LLC
Lookup
RDAP + WHOISanswers for it
DNSSEC
Signed1 DS record in the root
Level
Secondmybrand.citadel

Check a name

Names under .citadel cannot be registered, but ds will still tell you what the registry says.

Fills the command and the registrar links below in with your own name. The page is static — nothing is looked up here, and nothing you type leaves the browser.

ds mybrand --tld citadel

Add --where for the registrars and the registry's rules, --registry for the server that answered, or --all-info for everything at once.

What it costs

No registrar in the price table bundled with ds quotes .citadel, so the CLI prints no figure beside it — one of 927 such TLDs. That is a gap in the table as often as it is a TLD nobody sells, though here it is neither: the zone is closed. See Prices for supplying your own table with --pricing-file.

Who can register

Nobody outside Citadel Domain LLC — see the note at the top of this page.

How ds answers for it

RDAP first, WHOIS second — the same order for every TLD. .citadel has both, so RDAP answers and WHOIS is the fallback if it does not.

RDAP
https://rdap.identitydigital.services/rdapFrom IANA's bootstrap, refreshed when this page was built. The lookup is https://rdap.identitydigital.services/rdap/domain/mybrand.citadel — a 404 means the name is free.
WHOIS
whois.nic.citadelQueried on port 43, from the bundled whois.json. The name is called free when the reply contains domain not found — text matching, which is why RDAP is preferred where it exists.

ds mybrand --tld citadel --registry prints whichever of these answered. If a bundled WHOIS host has gone stale, IANA is asked who serves .citadel today. See Accuracy notes.

The registry

From IANA's delegation record for .citadel. .citadel is a generic TLD.

Run by
Citadel Domain LLCBased in United States of America. Delegated 2016-06-30, record last updated 2023-10-17.
Registry site
www.citadel.comWhere the registry documents .citadel — its rules, its accredited registrars, and any launch phases. Not a shop: registries sell wholesale to registrars, not to you.
Published services
rdap.identitydigital.services · whois.nic.citadelWhat the registry itself tells IANA it runs. They agree with what ds asks.
Name servers
a0.nic.citadela2.nic.citadelb0.nic.citadelc0.nic.citadelThe 4 authoritative servers for the .citadel zone — what the root delegates to. Nothing ds queries directly; they are what makes a registered name resolve.

What it is

Derived from the root zone and ICANN's registry list — each one is a fact with a source.

  • generic IANA Root Zone Database types it "generic"
  • brand ICANN records Specification 13 — a brand TLD, closed to the public
  • new-gtld ICANN delegated it on or after 2013-10-23, when the 2013 round opened — see delegated

In the root zone

The delegation itself, read out of the root zone — serial 2026090900, on 2026-09-09. The registry section above is IANA's record of what .citadel was delegated to; this is what the root actually answers with when a resolver asks it where .citadel lives.

Delegated to
  • a0.nic.citadel65.22.112.332a01:8840:6e::33
  • a2.nic.citadel65.22.115.332a01:8840:71::33
  • b0.nic.citadel65.22.113.332a01:8840:6f::33
  • c0.nic.citadel65.22.114.332a01:8840:70::33
The 4 name servers the root hands out for .citadel, with the glue addresses that come with them — every one of them answers over IPv6. None of this is what ds queries: these servers know which names exist, not who registered them.
DNSSEC
Signed — 1 DS record in the root
  • key 43942RSA/SHA-256 · SHA-2566A252BA4B61331A3D35B5D06AE744643AF83053295C42C0C2E65FCEBBA07834F
Each one is a fingerprint of .citadel's own signing key, published by the root and signed with the root's key — which is how a resolver that trusts only one key can prove an answer under .citadel came from its registry and was not tampered with in transit. It says nothing about who owns a name or whether one is free.

Ask the root yourself — no registry involved, and the same records this section was built from: dig +norec @a.root-servers.net citadel. NS and dig +norec @a.root-servers.net citadel. DS.

Also answered by rdap.identitydigital.services

and 438 more zones on the same server.