Seednote

Prefix

The registered issuance namespace

The registered issuance namespace at the start of an RID.

RSM ID Learning Center2 min read

The prefix is the part of an RID before the dot. It is one to sixteen decimal digits, with no leading zero except the single digit 0, and it names a registered issuance namespace. Prefix values are globally unique within the RSM identity registry and are never reused, even after retirement.

A prefix registry records each prefix's controller, issuance permissions, administrative delegation, validity status, signing-key information, and succession arrangements. The prefix tells a resolver where to begin verifying authority. It does not tell anyone who owns a particular resource, where the resource is hosted, or what kind of thing it is.

Example

In 451.7K4M9Q2X8D5P0R6T, the prefix is 451. 0451.7K4M9Q2X8D5P0R6T is not a canonical RID at all: the leading zero makes the prefix noncanonical, which is one of Document 09's parser vectors.

A common misconception

“The prefix identifies the owner.” A prefix identifies an issuance namespace. Ownership and operational management of an individual resource can change while its RID, prefix included, stays exactly the same. Another misreading treats the prefix as a domain or server; the specification forbids that inference.

The prefix is half of every RID. Who may issue under it is a matter of issuance authority, recorded in the registry. The registration Viewgraph follows a prefix from allocation to issuance.

In the specification

Syntax: Document 08 §3.1. Allocation and registry contents: §3.2. Never a hostname: §6.3.