IANA

Internet Assigned Numbers Authority

IANA is the organization responsible for coordinating the global Internet's unique identifiers — domain names, IP address numbers, protocol parameter values — under contract to ICANN (Internet Corporation for Assigned Names and Numbers) since 1998. IANA maintains the registries that define protocol parameters used across the Internet's core standards: HTTP, DNS, TLS, MIME, URI schemes, character sets, and hundreds of others. Each registry is the authoritative source of truth for the values that make the Internet interoperable.

IndustrySyntax IANA identifiers are protocol registries, not numbered standards. The identifier is a hierarchical registry slug: 'IANA <registry>[/<sub_registry>]'. The leading underscore in registry names (e.g. '_6lowpan-parameters') is part of the canonical form.

Doc Types

Components

Relations

Stages

Document Types 1

Protocol Registry

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Components 3

Structured elements that make up a IANA identifier:

Publisher

IANA — always emitted unless with_publisher=false

e.g.IANA

Registry

Top-level registry slug, kept verbatim (e.g. _6lowpan-parameters, uri-schemes, media-types)

e.g._6lowpan-parameters

:registry

Sub-registry

Optional sub-registry slug after the slash, kept verbatim

e.g.lowpan_nhc

:sub_registry

PubID Algebra 3

Relationships between IANA identifiers:

Relation	Description	Syntax	Example
Top-level Registry	Bare registry without sub-registry	`IANA <registry>`	`IANA uri-schemes`
Sub-registry	Registry with sub-registry partition	`IANA <registry>/<sub_registry>`	`IANA _6lowpan-parameters/lowpan_nhc`
Without Publisher	Bare index-key slug (no 'IANA ' prefix)	`<registry>[/<sub_registry>]`	`_6lowpan-parameters/lowpan_nhc`