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A permalink or permanent link is a URL that is intended to remain unchanged for many years into the future, yielding a hyperlink that is less susceptible to link rot. Permalinks are often rendered simply, that is, as clean URLs, to be easier to type and remember. Most modern blogging and content-syndication software systems support such links. Sometimes URL shortening is used to create them.

Contents

A permalink is a type of persistent identifier and the word permalink is sometimes used as a synonym of persistent identifier. More often, though, permalink is applied to persistent identifiers which are generated by a content management system for pages served by that system. This usage is especially common in the blogosphere. Such links are not maintained by an outside authority, and their persistence is dependent on the durability of the content management system itself.

History

In the early years of the web, all content was static, and thus all hyperlinks pointed at a filename. Soon, though, many web pages became dynamic, and many URLs began to include query terms.

One cited early use of the term permalink in its current sense was by Jason Kottke on March 5, 2000, in a post titled: "Finally. Did you notice the". [1] Matthew Haughey had discussed a permalink-style feature with Blogger co-founders Evan Williams and Paul Bausch the previous weekend, and Bausch had pointed out that it was technically feasible to produce permanent links in Blogger, using a feature (written by him) that allowed the ID of a post to be placed in a Blogger template. In response to Kottke's blog, on March 6, 2000, Haughey posted the technical details on his own weblog, [2] which helped open the way to widespread adoption.[ citation needed ]

Purpose

Permanence in links is desirable when content items are likely to be linked to, from, or cited by a source outside the originating organization. Before the advent of large-scale dynamic websites built on database-backed content management systems, it was more common for URLs of specific pieces of content to be static and human-readable, as URL structure and naming were dictated by the entity creating that content. Increased volume of content and difficulty of management led to the rise of database-driven systems, and the resulting unwieldy and often-changing URLs necessitated deliberate policies with regard to URL design and link permanence.

For example, Wikipedia's internal Common Gateway Interface-based URLs are made more readable by simplifying them. The internal URI for a Wikipedia article named Example, which is http://en.wikipedia.org/w/index.php?title=Example, is generated via URL rewriting from the more human-readable external URL, http://en.wikipedia.org/wiki/Example.

An entry in a blog with many entries is accessible from the site's front page for only a short time. Visitors who store the URL for a particular entry often find upon their return that the desired content has been replaced by something new. Prominently posting permalinks is a method employed by bloggers to encourage visitors to store a more long-lived URL (the permalink) for reference.

Permalinks frequently consist of a string of characters that represent the date and time of posting, and an identifier that denotes the author who initially authored the item or its subject. Crucially, if an item is changed, renamed, or moved within the internal database, its permalink remains unaltered, as it functions as a magic cookie that references an internal database identifier. If an item is deleted altogether, its permalink can frequently not be reused.

Permalinks have subsequently been exploited for a number of innovations, including link tracing and link trackback in weblogs, and referring to specific weblog entries in RSS or Atom syndication streams.

Comparing with PURL

Both permalink and PURL (persistent uniform resource locator) are used as a persistent URL, and redirect to the location of the requested web resource. The main differences in the concepts are about domain name and time scale: PURL uses an independent dedicated domain name, and is intended to last for decades; permalinks usually do not change the URL's domain, and are intended for use on timescales of years.

On Wikipedia, a permanent link to a specific version of an article is obtained from the "Permanent link" entry in the toolbox. Wikipedia permalink example.png
On Wikipedia, a permanent link to a specific version of an article is obtained from the "Permanent link" entry in the toolbox.

Many blogging and content management systems do not support versioning of content, that is, if an entry is updated, a uniquely accessible version is not created. Thus, in the context of these systems, a permalink may refer to different content over time. In the context of systems that support versioning, such as most wikis, a permalink is commonly understood as a link to a specific version. Here, both the link itself and the resource it refers to should not change over time.

MediaWiki, the software that runs Wikipedia, supports this type of permanent link. In its current implementation, old versions of specific articles, images, and templates are referenceable by unique unchanging URLs, though current entries may not use old versions of images and templates. Permanent links to specific versions are recommended for citing articles from sources such as Wikipedia and Wikinews, to ensure that the content remains unchanged for review. A reviewer can then view the cited revision, the current revision, and the differences between the two.

Presentation

Blog entries are usually laid out as follows:

Permalinks are usually denoted by text link (i.e. "Permalink" or "Link to this Entry"), but sometimes a symbol may be used. The most common symbol used is the hash sign, or #. However, certain websites employ their own symbol to represent a permalink such as an asterisk, a dash, a pilcrow (¶), a section sign (§), or a unique icon.

Permalinks can be indicated within the HTML of a page to allow automated browsing tools to detect the permalink and use it for linking instead of the stated URL. The link element should include the following attributes:

<linkrel="bookmark"href="http://example.com/bookmark/123/"/>

See also

Related Research Articles

A Uniform Resource Identifier (URI) is a unique sequence of characters that identifies a logical or physical resource used by web technologies. URIs may be used to identify anything, including real-world objects, such as people and places, concepts, or information resources such as web pages and books. Some URIs provide a means of locating and retrieving information resources on a network ; these are Uniform Resource Locators (URLs). A URL provides the location of the resource. A URI identifies the resource by name at the specified location or URL. Other URIs provide only a unique name, without a means of locating or retrieving the resource or information about it; these are Uniform Resource Names (URNs). The web technologies that use URIs are not limited to web browsers. URIs are used to identify anything described using the Resource Description Framework (RDF), for example, concepts that are part of an ontology defined using the Web Ontology Language (OWL), and people who are described using the Friend of a Friend vocabulary would each have an individual URI.

<span class="mw-page-title-main">Hyperlink</span> Method of referencing visual computer data

In computing, a hyperlink, or simply a link, is a digital reference to data that the user can follow or be guided to by clicking or tapping. A hyperlink points to a whole document or to a specific element within a document. Hypertext is text with hyperlinks. The text that is linked from is known as anchor text. A software system that is used for viewing and creating hypertext is a hypertext system, and to create a hyperlink is to hyperlink. A user following hyperlinks is said to navigate or browse the hypertext.

The Resource Description Framework (RDF) is a World Wide Web Consortium (W3C) standard originally designed as a data model for metadata. It has come to be used as a general method for description and exchange of graph data. RDF provides a variety of syntax notations and data serialization formats, with Turtle currently being the most widely used notation.

A Uniform Resource Name (URN) is a Uniform Resource Identifier (URI) that uses the urn scheme. URNs are globally unique persistent identifiers assigned within defined namespaces so they will be available for a long period of time, even after the resource which they identify ceases to exist or becomes unavailable. URNs cannot be used to directly locate an item and need not be resolvable, as they are simply templates that another parser may use to find an item.

<span class="mw-page-title-main">Link rot</span> Phenomenon of URLs tending to cease functioning

Link rot is the phenomenon of hyperlinks tending over time to cease to point to their originally targeted file, web page, or server due to that resource being relocated to a new address or becoming permanently unavailable. A link that no longer points to its target, often called a broken, dead, or orphaned link, is a specific form of dangling pointer.

<span class="mw-page-title-main">Digital object identifier</span> ISO standard unique string identifier for a digital object

A digital object identifier (DOI) is a persistent identifier or handle used to uniquely identify various objects, standardized by the International Organization for Standardization (ISO). DOIs are an implementation of the Handle System; they also fit within the URI system. They are widely used to identify academic, professional, and government information, such as journal articles, research reports, data sets, and official publications. DOIs have also been used to identify other types of information resources, like commercial videos.

URL redirection, also called URL forwarding, is a World Wide Web technique for making a web page available under more than one URL address. When a web browser attempts to open a URL that has been redirected, a page with a different URL is opened. Similarly, domain redirection or domain forwarding is when all pages in a URL domain are redirected to a different domain, as when wikipedia.com and wikipedia.net are automatically redirected to wikipedia.org.

<span class="mw-page-title-main">Web feed</span> Data format

On the World Wide Web, a web feed is a data format used for providing users with frequently updated content. Content distributors syndicate a web feed, thereby allowing users to subscribe a channel to it by adding the feed resource address to a news aggregator client. Users typically subscribe to a feed by manually entering the URL of a feed or clicking a link in a web browser or by dragging the link from the web browser to the aggregator, thus "RSS and Atom files provide news updates from a website in a simple form for your computer."

mailto is a Uniform Resource Identifier (URI) scheme for email addresses. It is used to produce hyperlinks on websites that allow users to send an email to a specific address directly from an HTML document, without having to copy it and entering it into an email client.

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This is a list of blogging terms. Blogging, like any hobby, has developed something of a specialized vocabulary. The following is an attempt to explain a few of the more common phrases and words, including etymologies when not obvious.

nofollow is a setting on a web page hyperlink that directs search engines not to use the link for page ranking calculations. It is specified in the page as a type of link relation; that is: <a rel="nofollow" ...>. Because search engines often calculate a site's importance according to the number of hyperlinks from other sites, the nofollow setting allows website authors to indicate that the presence of a link is not an endorsement of the target site's importance.

In the context of the World Wide Web, a bookmark is a Uniform Resource Identifier (URI) that is stored for later retrieval in any of various storage formats. All modern web browsers include bookmark features. Bookmarks are called favorites or Internet shortcuts in Internet Explorer and Microsoft Edge, and by virtue of that browser's large market share, these terms have been synonymous with bookmark since the First Browser War. Bookmarks are normally accessed through a menu in the user's web browser, and folders are commonly used for organization. In addition to bookmarking methods within most browsers, many external applications offer bookmarks management.

Clean URLs are web addresses or Uniform Resource Locator (URLs) intended to improve the usability and accessibility of a website, web application, or web service by being immediately and intuitively meaningful to non-expert users. Such URL schemes tend to reflect the conceptual structure of a collection of information and decouple the user interface from a server's internal representation of information. Other reasons for using clean URLs include search engine optimization (SEO), conforming to the representational state transfer (REST) style of software architecture, and ensuring that individual web resources remain consistently at the same URL. This makes the World Wide Web a more stable and useful system, and allows more durable and reliable bookmarking of web resources.

The FAO geopolitical ontology is an ontology developed by the Food and Agriculture Organization of the United Nations (FAO) to describe, manage and exchange data related to geopolitical entities such as countries, territories, regions and other similar areas.

The Handle System is the Corporation for National Research Initiatives's proprietary registry assigning persistent identifiers, or handles, to information resources, and for resolving "those handles into the information necessary to locate, access, and otherwise make use of the resources".

<span class="mw-page-title-main">Archival Resource Key</span> Form of URLs used as persistent identifiers

An Archival Resource Key (ARK) is a multi-purpose URL suited to being a persistent identifier for information objects of any type. It is widely used by libraries, data centers, archives, museums, publishers, and government agencies to provide reliable references to scholarly, scientific, and cultural objects. In 2019 it was registered as a Uniform Resource Identifier (URI).

Identifiers.org is a project providing stable and perennial identifiers for data records used in the Life Sciences. The identifiers are provided in the form of Uniform Resource Identifiers (URIs). Identifiers.org is also a resolving system, that relies on collections listed in the MIRIAM Registry to provide direct access to different instances of the identified records.

A Uniform Resource Locator (URL), colloquially known as an address on the Web, is a reference to a resource that specifies its location on a computer network and a mechanism for retrieving it. A URL is a specific type of Uniform Resource Identifier (URI), although many people use the two terms interchangeably. URLs occur most commonly to reference web pages (HTTP/HTTPS) but are also used for file transfer (FTP), email (mailto), database access (JDBC), and many other applications.

References

  1. ↑ "Finally. Did you notice the (kottke.org)". Archived from the original on 2022-12-22. Retrieved 2005-12-09.
  2. ↑ "Caroline wishes outloud for | A Whole Lotta Nothing". 6 March 2000. Archived from the original on 2011-07-16. Retrieved 2008-12-16.
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