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ARK Alliance

Home of the Archival Resource Key (ARK)

Overview of ARK organizations

Every ARK organization has a Name Assigning Authority Number (NAAN) listed in the public NAAN registry. Usually the NAAN representing a Name Assigning Authority (NAA) is a 5-digit number, but sometimes it is a shoulder, which is a few characters longer (e.g., “12345/x5”). Current registry data has not been loaded. Use the public NAAN registry link above for current records.

Each NAAN record includes the local organizational resolver to which the global Name-to-Thing (N2T.net) resolver will redirect ARKs that come in with that NAAN. Most ARKs, however, are published as URLs based at the local resolver (server) domain name, bypassing the global resolver.

Distribution of top-level domains (TLDs)

The range of top-level domains (TLDs), the final part of the domain name, across all local ARK resolvers is shown below. The table gives the count and percentage for every TLD in the current data. There is also a simple NAAN registry search interface.

All resolver TLDs

Registry data has not been loaded. Current records are available in the public NAAN registry.

Resolver registrations by top-level domain
TLD Registrations Percentage
Labeled bar chart of the most common TLDs. Smaller TLDs are grouped as "Other"; the table lists each TLD separately.

Organizations registered per year

The next chart and table show the number of newly registered NAANs per year. Choose a TLD to update both views. The table includes the count and percentage for every year in the selected data.

Annual registration data has not been loaded. Current records are available in the public NAAN registry linked above.

Visual summary of annual registrations. Exact values are listed in the table.
Annual registrations for all top-level domains
Year Registrations Percentage

Latest ARK organizations registered

Any memory organization can start creating ARKs once it obtains a NAAN, which may be requested at no cost by filling out the NAAN request form. Recent organization data has not been loaded. Use the public NAAN registry link above for current records.


    Page concept and JavaScript credit: Bob Coret, National Library of the Netherlands