HTML and CSS Reference
In-Depth Information
author, copyright, publisher, and so on. Finally, the topic can be found in numerous places
online. It may have a canonical location, but there are likely many others.
Information Resource
Unique ID
ISBN: 0-07-222942-X
Characteristics
Examples
Cost: 39.99
Author: Thomas A. Powell
Copyright: 2009
Locations
Examples
http://htmlref.com/
http://http://www.amazon.com/HTML-XHTML…
A new set of addressing ideas addresses these generic concepts. First, a uniform resource
name (URN) can locate a resource by giving it a unique symbolic name rather than a unique
address. Second, uniform resource characteristics (URC), describes a set of attribute/value
pairs that defines some aspect of an information resource. For example, in the case of a
book, a URC might describe a publication date, number of pages, author, and so on. The
form of a URC is still under discussion; however, logically what they would provide is
already being used often in the form of simple <meta> tags. Finally, the resource may have
location(s) on the Web where it lives. Taken all together, a particular information resource
has been identified. The collection of information, which is used to identify this document
specifically, is termed a uniform resource identifier (URI).
N OTE Occasionally, URI is used interchangeably with URL. Although this is acceptable, research
into the theories behind the names suggests that the term URI is more generic than URL and
encompasses the ideal of an information resource. Currently, a URL is the only common way to
identify an information resource on the Internet. Although technically a URL could be considered
a URI, this confuses the issue and obscures the ultimate goal of trying to talk about information
more generally than in terms of a network location.
Although many of the ideas covered here are still being discussed, some existing
systems already implement many of the features of URNs and URCs. Furthermore, many
browser vendors and large Web sites are implementing special keyword navigation
schemes that mimic many of the ideas of URNs and URCs. Unfortunately, as of the writing
of this topic, none of these approaches are widely implemented or accepted. URLs are likely
to remain the most common way to describe information on the Web for the foreseeable
future.
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