Archival Resource Key (ARK) identifiers are URLs that support long-term access to information. Learn below what you need to know about ARKs, whether you’re planning how your system or collection will use them, or you’re a developer building ARK tools.

ARK Anatomy

  https://example.org/ark:/12345/x54xz321/s3/f8.05v.tiff
  \_________________/ \__/ \___/ \______/\____/\_______/
              |        |     |      |      |       |
              |  ARK Label   |      | Sub-parts  Variants
              |              |      |
Name Mapping Authority (NMA) |    Assigned Name
                             |
              Name Assigning Authority Number (NAAN)

A peek at ARK anatomy. You can spot an ARK by its internal label.

Please note all ARK documentation has not yet been transferred to this site. This includes important ARK FAQs (Frequently Asked Questions) in English, French, and Spanish:

• FAQ about ARK identifiers 🇬🇧
• FAQ sur les identifiants ARK 🇫🇷
• FAQ sobre identificadores ARK 🇪🇸

Recommended for all users

ARK overview

• What ARKs are and why you would use them
• Identifiers and persistent identifiers (PIDs)
• Resolvers
• ARK structure
• How people are using ARKs
• Persistence means persistent management
• ARK Community Code of Conduct

Why ARKs?

• By 2001 there were 4 major PID types – this is why a 5th was needed.

ARK NAANs and systems

• Name Assigning Authority Number (NAAN) registry
• Nice Opaque Identifier (Noid) systems
• N2T: a global resolver
• N2T feature: suffix passthrough

ARK features

• Shoulders (local namespaces)
• Metadata
• Inflections: metadata and policy statement
• Deleting ARKS

Comparing ARKs, DOIs and other identifier systems

• Reasons to use ARKs as compared to DOIs
• What ARK, DOI, Handle, PURL, and URN have in common
• How ARKs differ from identifiers like DOIs, Handles, PURLs, and URNs
• Using multiple identifier systems
• When to use ARKs compared to DOIs, Handles, PURLs, or URNs

Getting started: what to plan for as you implement ARKs

• Get a Name Assigning Authority Number (NAAN)
• Decide what ARK features you need
• Choose (or build) an ARK system

Recommended for developers

The following in-depth information will be useful if you’re extending your own local repository or system with Noid software to support ARKs, or if you’re developing an ARK system.

General identifier concepts and conventions

• Terminology
• NAANs, prefixes, bases, and suffixes
• Shoulder practices
• Name Mapping Authority (NMA) services
• Resolution, N2T, Opacity, Test identifier conventions
• Base identifier extensions
• The “NCDA” check character convention

Running minters and resolvers

• Minting ARK name strings
• Best practices for minting ARK name strings
• Opaque identifiers
• Making server content addressable with ARKs
• ARK citation format
• ARK inflection vs. content negotiation

More about the N2T global resolver

• How N2T works
• N2T is not just for ARKs

ARK namespaces and sub-namespaces

• ARK namespace overview
• ARK shoulder as namespace
• Shared NAANs
• The NAAN’s role in N2T ARK resolution
• How to make changes to a NAAN

More about ARK shoulders

• Shoulder format
• Implementing shoulders

Testing ARKs with N2T

• Test with your own NAAN
• Request a shoulder under a shared NAAN

ARK implementation best practices

• ARK creation and object lifecycle
• Metadata
• Policy statements