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CDL Technologies Documentation

The following is a growing list of public-facing technical documentation from CDL’s various technologies, with an emphasis on metadata and identifiers.

CDL Technologies

Archival Resource Key (ARK) Identifiers

ARKs are URLs designed to support persistent, long-term access to information objects.

BagIt File Repackaging Format

BagIt is a set of hierarchical file system conventions designed to support disk-based storage and network transfer of arbitrary digital content.


Namaste (NAMe AS TExt) is a file naming convention to support primitive directory-level metadata tags exposed directly via filenames.

Name-to-Thing ( is a generic identifier resolver that recognizes over 600 identifier types and forwards requests to their respective servers.

Nice Opaque Identifiers (NOID)

NOID provides minting, binding, and resolving services in support of preservation-ready identifiers.


Pairtree is a file system convention for the organization of a digital object store.

YAMZ Metadictionary

The YAMZ Metadictionary is an open vocabulary of metadata terms from all domains and from all parts of “metadata speech”.