- affordability – there are no fees to assign or use ARKs
- self-sufficiency – you can host ARKs on your own web server
- flexibility – you can re- host ARKs on other servers without altering losing their core identities
- portability – you can host ARKs at a single well-known domain, ( such as n2t.net) , for global resolvability
Some unique advantages of ARKs:
- simplicity – access relies only on mainstream web "redirects" and ordinary "get" requests
- versatility – with "inflections" (different endings), an ARK should access data, metadata, promises, and more
- transparency – no identifier can guarantee stability, and ARK inflections help users make informed judgements
- visibility – syntax rules make ARKs easy to extract from texts and to compare for object variant and containment relationships
- reliability – an ARK URL retains its core identity even when hosted by different providers, whether in parallel or by future succession
To date about 100 organizations have registered to assign ARKs. Some of the largest users are
- The ARK Identifier Scheme Specification PDF version TXT version
- Towards Electronic Persistence Using ARK Identifiers (July 2003)
- ARK and UC3/CDL Identifier conventions
- Archival Resource Key - Wikipedia
- EZID service: long term identifiers made easy
- N2T resolver: Name-to-Thing
- NOID: Noid (http://): (Nice Opaque Identifier) Minting and Binding Tool
An ARK is represented by a sequence of characters that contains the label, "ark:", optionally . When embedded in a URL, it is preceded by the protocol name protocol ("http://") and hostname that begins every URL. That first part of the URLname of a service that provides support for that ARK. That service name, or the "Name Mapping Authority" (NMA), is mutable and replaceable, as neither the web server itself nor the current web protocols are expected to last longer than the identified objects. The immutable, globally unique identifier follows the "ark:" label. This includes a "Name Assigning Authority Number" (NAAN) identifying the naming organization, followed by the name that it assigns to the object.
UC3/CDL maintains a complete registry of all currently assigned NAANs, which is mirrored at the (U.S.) National Library of Medicine and the Bibliothèque nationale de France.
Any institution memory organization may obtain a NAAN and begin assigning ARKs. Because long-term identifiers often look like random strings of letters and digits, institutions organizations typically use software to generate (or mint, in ARK parlance) and track identifiers with software. To mint ARKs, you may use any software that can produce identifiers conforming to the ARK specification. CDL uses the open-source "noid" Noid (nice opaque identifiers, rhymes with "employed") software, which creates minters and accepts commands that operate them. The noid software documentation explains how to use noid not only to mint identifiers but also to serve as an institution's "identifier resolver".