MeridianMERIDIAN

Top-Level Domain (TLD)

technology.internet.top_level_domain

Domain extension (e.g., .com, .org, .uk). May include second-level domains for country codes (e.g., .co.uk). Does not include the dot.

Try a value

Top-Level Domain (TLD)'s rule accepts it.

Reads it as com

Also accepted by

Use it

Shell
finetype infer -i 'com' --mode column
# → technology.internet.top_level_domain
DuckDB
SELECT ft_infer('com');
-- → 'technology.internet.top_level_domain'
Cast template: {col} is your column
CAST({col} AS VARCHAR)
Casts to
VARCHAR
Membership list
tld
Standard

Pattern

Regular expression
^(?:[a-z]{2,}|xn--[a-z0-9]+)(?:\.[a-z]{2,})?$
ValueLengthShape
com3matches
org3matches
uk2matches
co.uk5matches
xn--3e0b707e12matches

Similar types

1 of the 12 other internet types accept every one of these samples on shape alone.

Going the other way, this type's own rule accepts 2 of 5 samples of Hostname and 1 of 3 samples of HTTP Method.

Background

Origin

A top-level domain is one of the domains at the highest level of the Domain Name System, directly below the root.[1] In a full domain name the top-level domain is the last non-empty label, so in www.example.com it is com.[1]

RFC 920, Domain Requirements, was written by J. Postel and J. Reynolds and published in October 1984.[2] RFC 920 introduced the limited set of top level domains.[2] RFC 920 lists the initial top level domain names as ARPA, GOV, EDU, COM, MIL and ORG, alongside country domains.[2] RFC 920 explains that general categories such as government, education or commercial were chosen to provide an organization name that is free of undesirable semantics.[2] RFC 920 defines a country domain as the English two letter code identifying a country according to the ISO standard Codes for the Representation of Names of Countries.[2] When RFC 920 was published, no country domains had yet been established.[2]

RFC 1591, Domain Name System Structure and Delegation, was written by J. Postel and published in March 1994.[3] RFC 1591 names the generic top-level domains of the time as EDU, COM, NET, ORG, GOV, MIL and INT.[3] RFC 1591 states that the IANA is not in the business of deciding what is and what is not a country.[3] Country codes are generally the two-letter ISO 3166 codes, though there are exceptions such as .uk.[1]

ICANN's New gTLD Program opened its first application round in 2012, and the first new gTLDs from that round were delegated to the root zone in October 2013.[1] Since 2009, countries with non-Latin scripts may apply for internationalized country code top-level domains, which use a Punycode-translated ASCII name in the Domain Name System.[1]

Use

IANA's registry of top-level domains lists each one with its type, such as generic or country code, and the organisation that manages it.[4] IANA records .uk as a country-code top-level domain managed by Nominet UK.[5]

RFC 920 describes top level domains as subdivided into second level domains, which may be subdivided into third level domains.[2]

RFC 5890 defines the ACE prefix xn-- as a string that appears at the beginning of every A-label, the ASCII-compatible form of an internationalised label.[6] IANA records xn--3e0b707e as the A-label of .한국, a country-code top-level domain for South Korea managed by KISA.[7] The same internationalised TLD can reach you as its xn-- A-label or in its native script, so convert one to the other before comparing values. (Meridian's view)

RFC 4343 clarifies that Domain Name System names are case insensitive.[8]

Sources

  1. [1]Top-level domain - Wikipediasecondary source
  2. [2]RFC 920: Domain Requirementsstandard
  3. [3]RFC 1591: Domain Name System Structure and Delegationstandard
  4. [4]Top-Level Domainsorganisation
  5. [5].uk Top-Level Domainorganisation
  6. [6]RFC 5890: Internationalized Domain Names for Applications (IDNA): Definitions and Document Frameworkstandard
  7. [7].한국 Top-Level Domainorganisation
  8. [8]RFC 4343: Domain Name System (DNS) Case Insensitivity Clarificationstandard

How it's detected

Pattern allows IDN (xn--) format.

Schema

https://meridian.online/schemas/technology.internet.top_level_domain · Frictionless type string

finetype taxonomy technology.internet.top_level_domain -o json-schema

Aliases

tld

Type Registry