Wikipedia:Citing sources/Further considerations

This page includes some additional considerations for citing sources. The information is here so as not to distract from content on the main Citing sources project page, which is designed to help newer editors get started quickly. This page provides additional information for interested editors.

The content of any webpage may alter of course, and may in time disappear completely. In any case where a webpage is referred to from an article, where it may be subject to future change or removal, the specification of an alternate archive URL will ensure link accessibility and stability. When referenced content can be retrieved from an archive source such as the Internet Archive or WebCite then archive information can be included along with the original reference information. Anticipating the possibility of future alteration or deletion, archive URL information can thus be added pre-emptively, at the time of a reference's initial inclusion and ahead of any potential issues with the original link.

The Internet Archive, also known as the Wayback Machine, allows on-demand archiving as well as periodically crawling web pages on its own schedule. Where possible and subject to copyright protection,[nb 1] it makes an archive copy of each page.

Enter the original URL of the web page of interest into the form at and then click BROWSE HISTORY to see if a particular URL has already been archived. Alternatively, prepend*/ to the URL of interest.

The next screen may show a calendar indicating the snapshot dates for all archived copies of that page. Click a date to see that archived copy. For some requested pages, the Wayback Machine will return an error message explaining why that particular page has not and cannot be archived.

If the page has not yet been archived, there may be a box near the bottom of the page with a link inviting the user to Save this url in the Wayback Machine. Clicking the link will show the current version of the requested web page and start the process that will attempt to archive the page. If successful, the archived copy will become available immediately the process is completed.

If the page has already been archived in the Wayback Machine, but you wish to save a new version (because the page changed since being last archived), you can archive it again by typing in the URL in your browser (where should be replaced with the URL of the document you wish to save). features on-demand archiving and it also has crawlers that automatically archive links on Wikipedia. When using the long form should be used // instead of the short form //

Many citation templates explicitly address pre-emptive archiving, including Template:Cite web and Template:Cite news (all Citation Style 1 templates do). These have the following parameters available:

For pre-emptive archiving, set |url-status=live. Later, if the external page goes down, someone can simply put |url-status=dead. The formatting of the reference is adjusted accordingly so the accessible link (the original or the archived version) is made prominent.

Archiving of a page being viewed can be easier with the use of bookmarklets. These cause the archiving to be performed by clicking on the bookmark.

When adding references it is sometimes necessary to clean up the referenced URL into a standard or canonical format.

These actions may include, but are not limited to those detailed below.

Although most browsers will treat both links the same, the trailing slash may give the reader a little more confidence that the stated URL has not suffered a cut and paste error or simple typo, such as or where or was meant.

Should a website change the site technology, and therefore the page name, from e.g. index.html or default.asp to index.php the longer format URL is likely to become a dead link. The final more basic URL is more likely to continue working.

Session IDs identify a single usage session by the original editor and should always be deleted from reference URLs.

Parameters used to track visitors should be removed from reference URLs.

Where a site has multiple URLs depending on which type of device the reader is using, choose the desktop version of the page URL where available. e.g. choose rather than the mobile site at

Editors will encounter these and many other situations. In all cases, apply common sense when making a decision. Above all, make sure the referenced URL works when it is accessed.

Wikilinks can be created from short note citations to their appropriate full references.[nb 2] For full details about using these wikilinks, see .

All of these methods produce this result. Note that clicking on the link in the footnote moves to the full citation, which in some browsers is then highlighted.

The Sun is pretty big,[1] but the Moon is not so big.[2] The Sun is also quite hot.[3]

There exists a tool that will provide sfn (Shortened foot note)s and (Named reference)s from URL / DOI / ISBN. It is a bookmarklet- ie, it is recorded on a browser as a bookmark, Ctrl-D and can be placed on browser's bookmark toolbar.