Contents

• Summary
• Bibliographic Information
• About the Open Archives Initiative (OAI)
• Principal References

The Open Archives Initiative has published an Implementation Guideline specification for Conveying Rights Expressions About Metadata in the OAI-PMH Framework. This specification defines mechanisms for data providers to associate XML-based rights expressions with harvested metadata that is queried and delivered via service providers using the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH).

Detailed examples are provided in the specification for declaring rights using the Creative Commons and GNU licenses; however, the rights expression mechanism under the OAI-PMH data model is agnostic as the particular rights expression language used by the data provider. The XML-based rights expressions indicate how data may be used, shared, and modified after it has been harvested.

The OAI Protocol for Metadata Harvesting (OAI-PMH) has now become the most widely adopted approach for publication of both "data" and "metadata" by online digital libraries and archive centers. A list of registered OAI conforming repositories (perhaps not current) identifies some 286 digital library projects using this federated database approach, and the OAIster Digital Library Production Service at the University of Michigan stores some 5,366,375 records of digital resources from 472 institutions.

The essence of the open archives approach is "to enable access to Web-accessible material through interoperable repositories for (meta-)data sharing, publishing and archiving. OAI develops and promotes a low-barrier interoperability framework and associated standards based upon open protocols. In the OAI model, a data provider maintains one or more repositories (web servers) that support the OAI-PMH as a means of exposing metadata; a service provider issues OAI-PMH requests to data providers and uses the metadata as a basis for building value-added services.

According to the online tutorial, OAI-PMH provides "a simple technical option for data providers to make their metadata available to services, based on the open standards HTTP (Hypertext Transport Protocol) and XML (Extensible Markup Language). The metadata that is harvested may be in any format that is agreed by a community (or by any discrete set of data and service providers), although unqualified Dublin Core is specified to provide a basic level of interoperability. MARCXML, METS, and OLAC are also popular supported formats. The OAI-PMH protocol is based on HTTP with support for flow control. Request arguments are issued as GET or POST parameters. OAI-PMH supports six request types, known as verbs; responses are encoded in XML syntax. OAI-PMH supports any metadata format encoded in XML, and OAI-PMH defines a single XML Schema to validate responses to all OAI-PMH requests."

The new OAI Guidelines document specifies the mechanisms by which rights expressions can be conveyed at three different levels representing OAI-PMH data model entities: the record level, the repository level, and the set aggregation level.

At the record level, metadata returned in OAI-PMH ListRecords and GetRecord responses "is packaged in <record> elements. Each <record> may include one or more <about> containers that provide information about the metadata. A rights expression can be associated with the metadata by including an optional <rights> package in an <about> container. The specification defines an XML schema to which such <rights> packages must conform. The schema allows for actual rights expressions to be specified by one of two mutually exclusive alternatives: in-line within a <rights> package, or by-reference via a URI of a network-accessible rights expression. In the by-reference encoding, there are no restrictions on the nature of the resource referenced by this URI; however, to facilitate machine processing, it is recommended that an XML formatted rights expression is accessible via the <rightsReference> URI."

At the repository level, "the response to the OAI-PMH Identify request contains information about the repository. This response may include one or more <description> containers that provide an extensible mechanism for repository description. This specification defines an optional mechanism for delivering, within a <description> container, a manifest of the rights expressions used in the repository. The purpose of this manifest, defined in an XML schema, is to provide a convenient way for harvesters to determine the rights expressions associated with metadata disseminated by a repository.

For rights expressed at the set level, the response to the OAI-PMH ListSets request contains information about the set structure of the repository. Sets are a mechanism to provide selective harvesting from a repository. This response may include one or more <setDescription> containers that provide an extensible mechanism for set description."

The editor's announcement for the Implementation Guideline on Conveying Rights Expressions clarifies how the guidelines specify a mechanism for including rights expressions that pertain to the contents of the <metadata> parts of records in OAI-PMH responses. No new rights expression language has been created. Instead, the specification provides a mechanism to include existing and future XML rights expressions. Description of rights expressions associated with set and repository aggregations is supported through manifests of rights expressions in set and repository descriptions. The design has been guided by the need for simple and clear semantics that will allow service-providers to make harvesting and use decisions based on these rights expressions."

The XML-based markup system for declarative rights expression for OAI-PMH exemplifies a growing preference for light-weight and medium-weight rights management for digital resources on the Internet. While the media industry tries to promlugate a uniform commercial DRM method for draconian rights restriction and enforcement, this goal has repeatedly failed, due to DRM patent terrorism and litigation about DRM patents, and the public lack of interest in fee-based software that invades personal computers. The OAI-PMH approach, like Creative Commons licenses and related solutions, places minimum importance upon legal enforcement: instead, it enables the creation of massive federated databases supported by unified search engines that allow consumers to identify digital content matching their requirements, and then to access digital assets using protocols based upon open standards.

The OAI-PMH Guideline on Conveying Rights Expressions notes that "actions in response to a failure of a harvester to abide by rights expressions are outside the scope of this specification." Harvesters "should look for and abide by the contents of any rights expressions included using this mechanism within records they harvest, [and] clients should act in good faith and abide by the rights expressions about the metadata they harvest."

The rapidly growing popularity of the "Commons" approach is understandable, especially when compared to the commercial DRM alternative, which tends to view every user as a pirate and a criminal. Public sensibilities about openness (open standards, open protocols, open source software, democratized open access to digital information), strengthened by the success of Google, Creative Commons, RSS/Atom, hundreds of public OAI-PMH repositories, and "the Worldwide Web" in general, are making it extremely difficult to convince consumers to pay for intrusive commercial DRM software that regularly prevents the user from doing something very sensible with digital information (select, copy, print, view-a-second-time, forward) that deserves to be used and shared on reasonable terms. The clear terms for "reasonable use" as supported by OAI-PMH rights expression and Creative Commons licenses provide an adequate model for many (perhaps most) use cases in a civil society that depends upon informed citizens.

In March 2005 the ODRL Initiative announced the release of the ODRL Creative Commons Profile as a Draft Specification. This draft "describes the semantics of the Creative Commons licenses and defines how they can be represented using a Profile of the ODRL rights expression language." The Open Digital Rights Language (ODRL) specification is a publicly available XML-based standard language and vocabulary for the expression of terms and conditions over assets. It covers a core set of semantics for these purposes including the rights holders and the expression of permissible usages for asset manifestations. Both ODRL and Creative Commons licenses use XML markup to express rights assertions in digital works, and neither has licensing requirements for use of the technology. In July 2004, the DCMI Usage Board announced approval of the rights-related terms "License" and "Rights Holder" in machine-readable metadata declarations for Dublin Core.