Interlanguage links are links from a page in one Wikipedia language to an equivalent page in another language

Interlanguage links are links from a page in one Wikipedia language to an equivalent page in another language. These links can appear in two places:These two types of links are created and handled differently and are discussed in different sections below.Pages on Wikipedia can have a list of equivalent pages in other languages. For example, the Irish Wikipedia has a page on Ireland titled “Éire”, so the English Wikipedia article on Ireland will link to the Irish one, and vice versa. For most people this list is shown on the left of the page, but this can be changed by changing the skin the site uses. This list is maintained in two places, Wikidata and the text of the page itself.Wikidata is a separate project to create a collaboratively edited knowledge base. Part of this project is to centralize the interlanguage links for all the Wikipedia projects. The Wikidata entry for a page contains (among other things) a list of links for that entry in different languages. This list of links is then used for the list shown on the page in Wikipedia.At the bottom of the Wikidata language list is a link labelled ‘Edit links’. Clicking on this will reveal two text boxes, one for the language and another for the article title. In the first box type in the language code, for example, for Irish use the code “ga”. In the second box, type the name of the article as it appears in that language’s Wikipedia. Then click save. You can get directly to the Wikidata entry for a page by clicking the link labelled ‘Data item’ in the Toolbox section of the sidebar. The link does not appear on pages that haven’t been linked to an item.If you get a message like “Site link … is already used by item Q….”, this means that there is already an item in Wikidata pointing to the article you are trying to link to. Wikidata does not allow more than one item to point to a single article in a Wikipedia. There are two cases:To edit an entry on Wikidata, click on the edit link next to the entry you wish to edit. A textbox will appear allowing you to edit the entry. Click on save when you are done.You can remove a page from the list of Wikidata’s links. To do so click edit, then click on the remove link.Before Wikidata, interlanguage links had to be recorded in the text of the page itself. The problem with this approach was that each language had to maintain its own separate lists. So for example, if the name of a page on the English Wikipedia changed, then each language that linked to that page would have to separately notice this fact and then change their own links.For most pages, these links are no longer needed and can be safely removed, but you should verify that the local list and the Wikidata lists match before doing so. There is an automated tool to help with that.The local links do however still serve some purposes:The local interlanguage links take the following form:where the language code is the two-letter code as per ISO 639-1. (See Complete list of language Wikipedias available. English is “en”, German is “de”, etc.) So for example in the English language article on Plankton, which is available on many other wikis, the interlanguage links might look like this:NOTE: These links are treated specially, and don’t show up in the body of the text, but in a special sidebar section “Languages” listed by language name. They can go anywhere in the article source as their placement does not alter the visual appearance of the links on the rendered page except for the order. However, the convention is to put them at the bottom of the page. Remember, you only need these type links if you are overriding the information from Wikidata, otherwise you should edit the links on the Wikidata entry.Featured or good articles are represented via Wikidata.Links between English Wikipedia pages and corresponding pages in the Wikipedias of other languages are handled via Wikidata; they are displayed in the “Languages” bar to the left of the article. To include, in some article, a link to a topic that is not covered by an article on the English Wikipedia but that does have a page in another language version of Wikipedia, there are three possible approaches:The advantage of the first approach is that the red link informs readers that the page does not exist locally, thus inviting its creation, and avoiding directing readers to a page that many of them will not understand. The disadvantage is that it conceals the existence of the foreign-language page, which might in itself be of interest to some readers, and may also be valuable to anyone wishing to create a corresponding English Wikipedia article.It is sometimes possible to combine the two approaches, giving a local red link in addition to an interlanguage link explicitly marked as such. For example: “…the plans were drawn up by German architect Hans Knoblauch (de)…” The templates {{ill}}, {{ill2}}, and {{ill-WD}} are designed to assist this combined approach.If a red link is not appropriate locally for whatever reason, such as because the subject does not appear to be notable, then linking a page in another language may be useful.Interlanguage links may also be useful outside of the mainspace for convenience, such as from one’s userpage to a page frequently visited or that like-minded visitors might want to go to.You can create a clickable link that will be visible in your text by adding a colon before and after the language abbreviation:These links look like this: fr:Jeux olympiques or ja:東京都. The language abbreviation is displayed, so the reader knows that they are links to the French article on the Olympic Games and the Japanese article on Tokyo.But if you wish you can use the pipe to show only the title:Which would look like this in your text: Jeux olympiques or 東京都You can also use the pipe trick to simplify this to: [[:fr:Jeux olympiques|]].
This gives the same result: a link to Jeux olympiques on the French Wikipedia.To link to a namespace other than the main article namespace, add the namespace after the language abbreviation. For example, the page for general discussions on the Japanese Wikipedia is located in the Wikipedia namespace. You can link to it as follows:On the English Wikipedia, links to pages that do not exist are displayed in a different color (usually red). But this check is not performed for links to pages on another wiki (including other Wikimedia Foundation sites). Unlike internal links, these links do not indicate whether the target page exists or not.[1] If the target page does not exist, the link leads a message on the target wiki informing you that the page does not exist and inviting you to create it.If you find interlanguage links to non-existent pages on the English Wikipedia, they may be deleted as having no content. Alternatively, you can create at least a stub page on the target wiki before adding an interlanguage link to it. Later, interested people can complete the rest of the page.Note: if the language prefix is wrong, it is considered to be part of the name of a page on the English Wikipedia. This page will probably not exist, so the link will be displayed in red.You can also link to Wikipedia pages in other languages by using external links, in the same way as linking to other sites on the Internet. This method should not be used in the body of an article, but it may be useful on User pages or Talk pages. For example, this method can be used to link to diff pages that show the editing history of a page on another Wikipedia.The following code:renders as:Templates {{Cross-wiki language diff}} and {{Cross-wiki language free diff}} are also available to construct diffs for other languages and projects, as is the special-page term :Diff/: [[:fr:Special:Diff/96480208]] will show the same diff as above.