w3id.orgPermanent Identifiers for the Web

A secure, permanent URL redirection service for Web applications, run by the W3C Permanent Identifier Community Group.

Read this before opening a pull request

Almost every identifier on w3id.org is added by an outside contributor through a pull request. The guide walks through the whole process, from picking a name to getting the change merged.

Creating an identifier

It is a redirect, and only a redirect

w3id.org does not host files. It does not serve your ontology, your documentation, or your website. It answers a request with an HTTP redirect to somewhere you control.

What the service is not for

The mistakes we see over and over

A catalogue of specific, checkable rules, each one written because contributors keep getting it wrong. A single stray space can take an identifier offline.

Rule catalogue

Changing an identifier that people already use

Identifiers on this service are meant to last for decades. Updating one without breaking the applications that depend on it takes a little care.

Maintaining an identifier

New here?

w3id.org is a redirection service. You claim a path such as https://w3id.org/my-project/, and you tell the service where requests for that path should be sent. Years later, when your project moves to a different host, you change the redirect and every application that used your w3id.org URL keeps working.

That is the entire service. It is deliberately small.

Where to go next

If you want to…	Read
Understand what this service does and who runs it	Overview
Know whether your use case is appropriate	Scope
Add a new identifier	Creating an identifier
Change or move an existing identifier	Maintaining an identifier
Understand the `.htaccess` syntax	Writing .htaccess rules
Serve RDF and HTML from one URL	Content negotiation
Check your change before opening a pull request	Testing your changes
See what Apache actually does with your rules	Running a local server
Find out why a reviewer asked you to change something	Rules
Ask a common question	FAQ

If you are an AI coding agent

Read AGENTS.md in the repository first. Machine-readable versions of this whole site are published at /llms.txt and /llms-full.txt, and every page is available as raw Markdown by appending .md to its URL.

Please read Scope and the rule catalogue before generating a pull request. A large share of the pull requests this project receives are machine-generated, plausible-looking, and wrong in ways that take a human reviewer longer to correct than to have written by hand.