Namespace ID: urn-3 Registration Information: Version 2 Date: 2009-01-27 Declared registrant of the namespace: Name: Andrea Goethals E-mail: nrs-ns-adm&hulmail.harvard.edu Affiliation: Harvard University Library Address: Office for Information Systems 90 Mt. Auburn Street Cambridge, MA 02138 The named registrant is specified in her capacity as the namespace administrator for the Harvard University Library Office for Information Systems (HUL/OIS). In the future, other individuals may be designated by HUL/OIS for the purposes of administering potential updates to this registration. Declaration of syntactic structure: All URNs defined under the namespace have the following structure, specified in ABNF notation [1]: urn = "urn:" nid ":" nss nid = "urn-" n n = number-assigned-by-IANA nss = authoritypath ":" resourcename authoritypath = authority / (authoritypath "." authority) authority = 1*authoritychar authoritychar = upper / lower / number / "(" / ")" / "+" / "," / "-" / "=" / "@" / ";" / "$" / "_" / "!" / "*" / "'" / ("%" hex hex) resourcename = 1*resourcechar resourcechar = authoritychar / "." / ":" where , , , and are defined in Section 2.2 of [4]. The %-escaping mechanism, as described in Sections 2.2 and 2.3.1 of [4], is used to incorporate into URNs characters that are not explicitly allowed by the grammar. Examples of valid URNs defined under the namespace include: urn:urn-:FHCL:10403 urn:urn-:HBS.Baker.TC:1923 urn:urn-:HUL.Eresource:holliswb urn:urn-:HUL.OIS:Home The component of the URN uniquely identifies the naming authority under which the URN was assigned. A naming authority is an administrative unit or agent that has been granted the privilege of creating, and the responsibility for maintaining persistently, names in the subset of the full namespace identified by that authority's . Naming authorities exist within a tree-like structure of authority delegation, under which any given naming authority derives its privileges and responsibilities from a pre-existing parent authority. Naming authorities may independently propose and enforce local policies and administrative procedures relative to names created within their scope. The administrator of a naming authority, regardless of its position within the delegation tree, has full oversight and operational control over all aspects of URN administration of all delegated authorities that derive from the common parent. The root naming authority for the namespace is administered by HUL/OIS. The root authority exists solely to provide a common root of delegatable naming authority; it alone has no corresponding . Relevant ancillary documentation: [1] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, November 1997. [2] Daniel, R., "A Trivial Convention for Using HTTP in URN Resolution", RFC 2169, June 1997. [3] Mealling, M. and R. Daniel, Jr., "URI Resolution Services Necessary for URN Resolution", RFC 2483, January 1999. [4] Moats, R. "URN Syntax", RFC 2141, May 1997. [5] Shafer, K., S. Weibel, E. Jul, and J. Fausey, "Introduction to Persistent Uniform Resource Locators", Proc. INET '96, The Internet: Transforming Our Society Now, Montreal, June 24-28, 1996. Identifier uniqueness considerations: Individual naming authorities are responsible for insuring the uniqueness of the components of the URNs created within their scope. Naming authorities are also responsible for insuring the uniqueness of the terminal component of the for all delegated authorities. Identifier persistence considerations: HUL provides an administrative system that maintains URN registration within the namespace. The system insures that once a URN is assigned it is never reassigned to a different resource. Process of identifier assignment: The administrative system is decentralized to allow individual naming authorities to create and maintain independently the URNs that fall within the scope of those authorities. Administrative units or agents wishing to assign URNs must be granted the appropriate privilege to do so from the administrator of the naming authority in the scope of which the URNs are to be created. Similarly, units or agents wishing to administer a new delegated naming authority must negotiate directly with the administrator of the potential parent authority, who, if acquiescent, will create the delegated authority. Process for identifier resolution: HUL provides a resolution service for the namespace. The service accepts THTTP-formatted [2] resolution requests for the URN-to-URL and URN-to-URLs services (specified by either the "N2L" and "N2Ls" mnemonics of [2] or the "I2L" and "I2Ls" mnemonics of [3]). Server responses are consistent with [3]. Multiple URLs associated with a single URN are maintained within the resolver database in an ordered list. A URN-to-URL request against a URN with multiple URLs returns the URL with the highest priority in the list. The mechanism used by client user agents to determine the location of the resolution service is outside of the scope of this registration document. In the absence of widely available native support for URNs within the current generation of web clients, the resolution service also accepts requests in a PURL-like syntax [5] for URNs that are encapsulated into URLs: http:///urn-:: In this case, the URN-to-URL resolution service is assumed by the resolver. Rules for Lexical Equivalence: The entire URN is case-insensitive. Conformance with URN syntax: No special considerations. Validation mechanism: The administrative system performs syntactic validation of all URNs at the point of their registration. Scope: This namespace is used for the identification of network-accessible resources delivered to the Harvard community and the public through the mediation of HUL-supported systems or other delivery mechanisms controlled or directed by Harvard-affiliated entities whose standards and procedures for resource maintenance and access are consistent with those of HUL, or for resources made accessible to the Harvard community under contractual or similar arrangements. These resources are provided by various organizational units of Harvard University, including administrative and academic departments, libraries, and museums, as well as digital content purchased or licensed from external vendors. (01/28/10) []