Help:Link

s allow users to easily move between pages. For basic information about wiki-markup in general, see Help: Editing.

With MediaWiki it is not possible to code hyperlinks using HTML. Instead there are three general types of hyperlinks, each with associated to distinguish them: wikilinks, interwiki links, and external links. Besides linking, each provides important additional features specific to wikis, such as automatic broken-link detection for wikilinks, and automatic numbering of external links when used as references.

Wikilinks
A wikilink is an to another page or page-section within the same. MediaWiki automatically checks if the target of a wikilink exists (""). If the page doesn't exist, the link leads instead to the editing screen, and it is assigned the class "new". Such wikilinks are nicknamed "red links" because they are colored red in the default stylesheet on a default installation of MediaWiki. "Red links" are useful in determining the current status of the page (created or not created), create links to future pages, and facilitate and encourage creation of new pages. Also, through "What links here" applied to the non-existing page they provide indirect links to other pages with the same red link.

A link to a non-existing page in the MediaWiki namespace for an existing system message counts as a link to an existing page.

Syntax
MediaWiki defines a wikilink as a closed set of inward facing square bracket pairs "  ". The link target is the sequence of characters immediately following the first bracket pair until a pipe "|" or the opposing bracket pair "]]" is encountered (read from left to right). The link target can be another page on the wiki, a section on the same page as the link, or a section on another page on the wiki.


 * Inter-page links: Links of the form  link to the page that exactly matches that "page_name".


 * Intra-page links: Links of the form  link to the first section on that same page, that has a heading (or anchor – see below) which exactly matches that "link_name".


 * Inter-page "intra" links: Links of the form  link to the matching section of the matching page, see section linking.

The wikilinks syntax also includes various formatting options to control how a link and its visible text appear.

* Links with parameters (the link name) are said to be "piped" because of the pipe symbol used. See Help: piped links.

** Regardless of whether the prefix is an interwiki link prefix, a namespace prefix, or just some text with a colon.

*** Does not work with #-wikilinks (intra-page links): renders any as pure text.

Note that the image, category, and interlanguage syntax are the same as the wikilink syntax. Attempting to link normally will place the image on the page, add the page to the category and create an interlanguage link at the edge of the page. This can be prevented by prefixing a colon, which escapes the specific syntax. For example,,  , and.

In the case of a link to a local, non-existing, dynamically generated image description page of an image on Commons, this page is counted as existing for links on pages, e.g. File:Cow-on pole, with horns.jpeg, but not for links in edit summaries and logs.

The existence of an internal link from a page to an existing or non-existing page is recorded in the pagelinks table.

Stub feature
A wikilink to an existing page will be in class 'stub' if the page is in the main namespace, it is not a redirect, and the number of bytes of the wikitext is less than the "threshold for stub display" set in the user's preferences.

This allows users to immediately identify links to very short pages that probably need to be expanded. Alternately, a user may set a very high threshold to achieve any of the following:
 * Identify links to very large pages. However, the criterion is the size of the wikitext; possible inclusion of templates and images can make the rendered page large, even if the amount of wikitext is small.
 * Determine at a glance whether a link leads to the main namespace or not. However, this does not take into account redirects to the main namespace (even if the redirect itself is in the main namespace).
 * Identify links to redirects, for clean-up work such as bypassing redirects.

However, section linking to a "stub" does not work. Although this is normally a minor issue, this may cause problems with users who set a very high threshold.

Interwiki links
An interwiki link links to a page on another website. Unlike what the name suggests, the target site need not be a wiki, but it has to be on Wikia's interwiki map. These links have the associated CSS class "extiw". These are in the same form as wikilinks above but take a prefix which specifies the target site. For example,  links to the main page of the English Wikipedia. The prefix can be hidden using the same piped syntax as wikilinks.

An interwiki can also link to a section or other anchor; see section linking.

Interwiki links back to same project
Although interwiki links can be used to point to a wiki from itself, this is not generally recommended. MediaWiki does not detect whether or not the target page of an interwiki list exists, so there is no special formatting and the link is always to the view page. Further, MediaWiki does not check if the page is linking to itself. A self wikilink is bolded (like :), whereas a self interwiki link is normal (memoryalpha::).

Pros:
 * A copy of the wikitext on a sister project may still point to the same page. Sometimes two prefixes are needed for that purpose, e.g. a.

Cons:
 * Link has non-standard appearance
 * No existence-detection for target page

E-mail links
Links to an e-mail address work the same way that external links do, except they require the prefix. E-mail links are in the form of  (resulting in [mailto:anyone@example.org address name]), with the link name separated from the address by a space. Addresses without names will automatically be numbered:  becomes [mailto:anyone@example.org]. Again, links with no square brackets will be displayed in their entirety: mailto:anyone@example.com.

Same project, special page
External links support various special optional URL parameters in their linking-code. These allow links directly to the edit history of a page, to a page in edit view, a diff of two versions, etc. They can also be used to create a navigational image.

For portability, use the "fullurl" parser function where the URL should depend on the project.

Globe icon
The Memory Alpha MonoBook skin produces an globe icon after every external link. This can be suppressed with class="plainlinks":


 * gives [http://a a]
 * gives [http://a a]

PDF icon
External links to PDF files have their own icon; for example, http ://a.pdf results in http://a.pdf.

Skipping a number
To skip a number in the automatically numbered external links (for whatever reason), use, for example, [http://a] :  [http://a].

Note that counting the links is done after expansion of templates and parser functions.

Linksearch
Special: Linksearch (an extension installed on Wikia wikis ) finds all pages linking to a given URL. Using the externallinks table, it provides, for a given external link pattern, a list of source page names (linked) for each full link target (also as a link). One can either search all namespaces or a selected one. A leading wildcard * can be used to search links to a whole (for example, ), or a  (for example, ), etc. In the case that a full domain name is specified, one can additionally specify the rest of the URL, or the first part of that (a wildcard at the end is implied), for example.

Remarks:
 * Do not enter the "http://".
 * The colon in the URL may cause the link search to return no results.
 * A MediaWiki page name in a URL has underscores instead of spaces. Also the URL specified in Linksearch requires using underscores.
 * Even if multiple URLs lead to the same target, with regard to capitalization, multiple underscores, and using "index.php" or not, Linksearch is case-sensitive and also does not find alternatively written URLs. Therefore, when creating an external link, for optimal use of Linksearch, use a canonical form for the URL. In particular, if after following a link the address bar shows a modified URL, change the URL in the link to that.
 * The list is alphabetic in the URL. Note that an underscore, unlike a blank space, is alphabetically positioned between "Z" and "a".

Backlinks
Commonly, a link to a normal page on the same project is in internal link style. An advantage is the existence detection. Also, if some links are in internal and some in external link style, we need both "What links here" and Linksearch for finding all backlinks. However, especially for a link to a section or explicitly-set anchor, one could put an internal link and also, with CSS style "display=none", an external link, to provide backlinks.

External link style is also superior to interwiki link style. The URL specified for Linksearch can even contain an anchor (see below), or the first part of an anchor. Therefore Linksearch can find backlinks of sections and explicit anchors. In this regard external links are even superior to internal links. We can combine the advantages of internal and external link style by putting both, but hiding the external links: http://...

Linking to anchors
Links of the form  will link to the first anchor on the page matching that "anchor_name", usually the first identical section heading.

An #anchor_name can also be appended to the page name in any type of link, thus linking to the first identical section heading (or anchor) of the named page:

Automatic anchors
Section headings automatically act as anchors, with the heading text as the "anchor_name". In the case of multiple sections with identical headings, the anchor name of each has "_2", "_3", etc. appended, starting from the second occurrence.

The anchor links to the table of content of the page, unless there is a section titled "toc".

Manual anchors
Manually-set anchors are useful for linking to "unlinkable" things like a table (title or cell), a section of plain text, etc. For example, in the Wikilink Tricks & Demos table above, though the "Wikilink Tricks & Demos" title text appears like a minor heading, it is not, and the otherwise perfectly normal wikilink  will not work.

There are a number of ways to set an anchor at an arbitrary position:


 * On some wikis, a template called "anchor" exists, for example anchor and wikipedia:template:anchor, providing a simple, standardized method for that wiki.


 * Generic anchors, such as . For a hidden anchor, omit the text.


 * Manual HTML headings (discouraged): .  Text is anchor_name.


 * In some cases, inserting an HTML-like ID attribute into an (existing) wiki element. For example, from the Wikilink Tricks & Demos table above:




 * The reserved name  always links to the top of a page.

See also Help:Section.

Linksearch anchors
As mentioned above, if the external link style is used, e.g., we can use Special:Linksearch:.

Since Linksearch allows specifying the first part of an anchor, it is useful, if anchor names are numerical or have a numerical end, to use leading zeros. Otherwise, when searching for links to, for example, "1", we also get links to "10", etc. This is e.g. applied in wikipedia:Portal:Current events/DateHeader2. More generally, if there are anchors "a" and "ab", it may or may not be desired that a search for links to "a" also gives links to "ab"; if not, use an anchor like "_a".

Index-style anchors
If anchor names have multiple components, it is useful to put the most significant component first; for example, if anchors indicate months or dates, we could use the format YYYY-MM, or YYYY-MM-DD, or in a year page MM-DD (see also ), with leading zeros (see also Date formatting and linking at Meta). This also applies to page names, but since these are highly visible, as opposed to anchors, other considerations play a role too. In the case of sections, if for link targets another naming scheme is desired than for the display of section headings, explicitly place anchors instead of using section names. This is used in wikipedia:Portal:Current events/DateHeader2, where the use in links of the names of explicitly placed anchors is enforced by using pseudo-sections, with displayed headings that cannot be used as anchors.

Anchors in external links (anchorencode)
In an external link, an anchor can be created conveniently with the parser function "anchorencode"; for example,  ""  gives "" which can be used to form the link #

Subpage feature
MediaWiki has a subpage feature which is active on Memory Alpha outside of the main name space.

A of pages is established by using forward slashes in pagenames: A/b is a child of A, hence A is a parent of A/b; also A/b/c is a child of A/b; while A/a, A/b, and A/c are siblings. At the top of the subpage body, links to all ancestor pages are shown automatically, without any corresponding wikitext. The links show up even if the parent page does not exist, but the sequence of ancestors stops before any non-existing ancestor page (e.g., if the grandparent page does not exist, the parent page is not shown either). Like most letters of a page name, the first letter after the slash is case-sensitive; "/subpage" and "/Subpage" are different pages.

What links here and Related changes ignore these automatic links.

Note that any slash in a page name causes a subpage structure, even if unintended.

Variables
On page A:B/c/d, where A is a namespace, yields B/c and  yields d.

Relative links
Inside a subpage hierarchy the following relative links can be used:
 * ../ links to the parent of the current subpage, e.g., on A/b it links to A, on A/b/c it links to A/b.
 * ../../ links to the grandparent of the current subpage, e.g., on A/b/c it links to A.
 * ../s links to a sibling of the current subpage, e.g., on A/b, it links to A/s.
 * ../../s links to an "uncle" of the current subpage, e.g., on A/b/c, it links to A/s.
 * /s links to a subpage, e.g. on A it is the same as A/s.

See also, and the example pages Link/a/b and m:Help:Link/a/b.

User space
Subpages of a user page are considered to be in that user's "user space".

Character conversion
In accordance with the rules explained in Help: Page name, conversions are automatically made to non-literal characters in wiki and interwiki links. For example, " " becomes "Help:Page name". However, the opposite is true for external links; literal characters are converted into non-literal characters. For example, most browsers will convert ".../wiki/!" to ".../wiki/%21".

A code like %70 in a redirect disables it, although the link works from the redirect page. For a redirect that works, the redirect page shows the canonical form of the target, unlike its preview page, which renders the link in the usual way.

Additional effects of links

 * Related changes
 * Backlinks, Linksearch
 * Date formatting
 * Using a space after the pipe syntax produces (depending on the browser) a space only, not a link (" "), but it is treated as a link for the "What links here" feature.

"Hover box" on links
On some browsers, holding the cursor over link will show a hover box containing the text of the link's HTML title attribute. MediaWiki sets this to the target page name (without the possible section indication) if it's a wikilink (the message with id 'red-link-title' if the page does not exist), the page name with prefix if it's an interwiki link, and the URL if it's an external link.

This can be switched off in the user preferences. The browser may also show similar info, but with the possible section indication, in the status bar.

For these effects a piped link is useful even if it not followed to the target; for example, for displaying the meaning of an acronym (e.g. NPOV) or any other remark. It is possible to produce a hover box without a link; see. It is also possible to change the contents of the hover box, using linktip. For example, would produce.

Links from a page
With the Query API, the links from page "pagename", sorted by namespace, and for each namespace alphabetically, are given by /query.php?what=links&titles=pagename, e.g.  /query.php?what=links&titles=.

Linking to a page from an image
It is possible to use images as links to other pages. For more information, see using an image as a link to a page.