Uniform Resource Identifier

Term used by the W3C consortium for labels used for web content. URIs include both Uniform Resource Locators (example: http://subdomain.domain/name1/name2...) and Uniform Resource Names (example: urn:domain:subdomain:name1:name2...).

Implementing Persistent Identifiers

This document, by Hans-Werner Hilse and Jochen Kothe in November 2006, is a fairly complete reference to key issues on Persistent identifiers. It discusses various types of identifiers including Handles, Digital Object Identifiers (DOIs), Archival Resource Keys (ARKs), Persistent Uniform Resource Locators (PURLs), Uniform Resource Names (URNs), National Bibliography Numbers (NBNs), and the OpenURLs. Examples and references are provided for each type of identifier.

URN Namespace for OGC

Document by Carl Reed on the URN namespace for OGC.

International Resource Identifiers (IRIs)

International Resource Identifiers may replace URIs in a lot of Semantic Web activities. URLs are limited since the construct can use only ASCII characters, while IRIs can contain characters from the Universal Character Set ISO/IEC 10646.

IETF Internet Engineering Task Force, RFC 3986: Uniform Resource Identifier (URI)

IETF Internet Engineering Task Force, RFC 3986: Uniform Resource Identifier (URI): Generic Syntax, in T. Berners-Lee, F. R. and L. Masinter, eds., 2005, http://www.ietf.org/rfc/rfc3986.txt.

GML Object Identifiers

This document by the SEE GRID community describes GML object identifiers (providing many examples)/

Cool URIs Don't Change

This document argues for the feasibility and value of maintaining Uniform Resource Identifiers (URIs) indefinitely. It finds the both Universal Resource Names (URNs) and the familiar Universal Resource Locators (URLs) should remain the same (and in the case of URLs, resolvable) indefinitely, through good design and implementation practices.

Encoding URIs in ISO 19139

ISO 19139 is the application of the ISO 19115 Geospatial Metadata Standard. It is being used to describe resources within Catalog Services for the Web (CSW). A resource can be, among others, a layer, an observation, a coverage, or a feature. These could be served respectively as WMS, SOS, WCS, and WFS. Ideally we would like to discover these resources registered in a catalog by using controlled vocabularies and relation that can exists among terms.

URIs: What, Why, and How?

Definition of URIs

A URI, or Unique Resource Identifier, is a Web naming/addressing technology that uses short strings to refer to resources in the Web. These resources could be Web Documents, services, electronic mailboxes, images, downloadable files, or other electronic entities. URI encompasses both URLs (Universe Resource Locators) and URNs (Uniform Resource Names).

MMI Guide for an Ontology Provider 20070205 (deprecated)

(This file is kept for historical purposes, but is no longer the current document. The current document is at http://marinemetadata.org/apguides/ontprovidersguide.)

Click here to get the file

Size 68.0 kB - File type application/msword

Citations - They're Not Just for Publications Anymore

By definition, metadata exists to describe data or information. Descriptive metadata enables appropriate use, and facilitates re-use of data. Once data has been discovered and used, it should be cited. Publications frequently reference data sets, but the question remains - how should authors cite data?

As part of its Data Policy, the International Polar Year (IPY) indicates


Subscribe to RSS - Uniform Resource Identifier