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RDAP ccTLD Support

Not all country-code TLDs (ccTLDs) participate in the RDAP protocol. domain-scout skips RDAP lookups for TLDs that are known to return 404 from the rdap.org bootstrap service, avoiding unnecessary HTTP round-trips and noisy error logs.

Source: IANA RDAP Bootstrap Registry

ccTLDs with RDAP support (in IANA bootstrap)

These TLDs are served by rdap.org and return structured registration data:

.ar .au .br .ca .cz .fi .fr .id .in .nl .no .pl .sg .si .th .tw .uk

Generic TLDs (.com, .net, .org, etc.) are also fully supported.

ccTLDs with RDAP but no useful registrant data (GDPR)

Some European registries participate in the RDAP bootstrap but redact all registrant fields due to GDPR. The response is valid JSON but contains no actionable org/name/country data:

  • .de (DENIC)
  • .ch (SWITCH)

These are included in the skip list because the lookup cost produces no corroboration value.

ccTLDs without RDAP (skip list)

These TLDs are not in the IANA RDAP bootstrap registry. Requests to rdap.org return HTTP 404. domain-scout skips them automatically:

.ae .at .be .bg .ch .cl .cn .co .de .dk .edu .ee .es
.hk .hr .hu .ie .il .io .it .jp .kr .lt .lu .lv
.mx .my .nz .pe .ro .ru .se .sk .tr .us .za

Note: .edu is not a ccTLD but is also absent from the RDAP bootstrap.

Why no WHOIS fallback?

WHOIS (port 43) is an older protocol that most registries still support. However, implementing WHOIS fallback for skipped TLDs was not pursued for several reasons:

  1. Per-registry parsing: Every WHOIS server returns free-form text in a different format. There is no standard schema. Supporting N registries means N parsers.
  2. GDPR redaction: European registries (and many others) redact registrant fields in WHOIS responses, returning "REDACTED FOR PRIVACY" or equivalent. The data is not there to parse.
  3. Rate limiting: Many WHOIS servers aggressively rate-limit automated queries (e.g., DENIC limits to 1 query/minute).
  4. Marginal ROI: RDAP corroboration is one signal among several (CT logs, DNS, similarity scoring). Missing RDAP data for a subset of TLDs has minimal impact on overall confidence scoring.