Editing Help:Citation Style 1 (section)

===External links===
* '''url''': Adds a link to the title
* '''chapter-url''': Adds a link to the chapter.
* '''format''': Format of the document at its URL (e.g., PDF, XLS, etc.). Do not specify for HTML as it is implied as the default.  Do not use this parameter for completely different purposes, with annotations such as "fee required" or "reprint"; its intent is to notify readers what the file format is (e.g. in case some browsers might have trouble with it, or some might prefer to save the link to disk rather than open it in the browser). Access restrictions can be shown using the appropriate {{para|url-access}} parameter, see [[#Registration or subscription required|Registration or subscription required]]. Other notes about reprintings, etc., should be placed after the template, and before {{tag|ref|c}}.

====Using |format= ====
When MediaWiki encounters an external link URL with a '.pdf' or '.PDF' [[filename extension|extension]], it renders the external link with a [https://example.com/document.pdf PDF icon] in place of the usual [https://example.com/document external-link icon].  To make rendered cs1|2 citations that link to PDF documents somewhat more accessible, cs1|2 automatically adds a parenthetical PDF annotation so that those readers using screen-reader technology can know the type of the linked file.  This is imperfect because some on-line sources redirect .pdf URLs to .html landing pages (this is common for PDF documents behind paywalls or registration barriers).  Because the parenthetical PDF annotation happens automatically, editors are not required to set {{para|format|PDF}}, though doing so causes no harm.  The {{para|format|PDF}} parameter may be deleted as part of a more substantial edit but editors should consider that many cs1|2 templates are copied from en.Wikipedia to other-language Wikipedias when articles here are translated to that other language.  Do not assume that other-language Wikipedias use up-to-date cs1|2 templates; many do not, so removing {{para|format|PDF}} here can affect readers/translators at other Wikipedias.

====Online sources====
{{Main|Wikipedia:External links|Wikipedia:Citing sources}}

Links to sources are regarded as conveniences and are not required, except when citing Web-only sources. There are many digital libraries with works that may be used as sources.
* Links should be to full versions of the source.
* Online sources that require payment or subscription may be included per [[Wikipedia:Verifiability]].

Do not link to:
* Sites that do not have permission to republish the work or that otherwise violate copyright.
* Commercial sites such as Amazon, unless no alternative exists.
* Reviews of the work.
* Very short extracts such as Google Books snippet view where there is not enough context to verify the content, unless the entire work is also freely available there. (See [[WP:BOOKLINKS]])

====Link formats====
Links should be kept as simple as possible. For example, when performing a search for a Google Book, the link for ''Monty Python and Philosophy'' would look like:
: https://books.google.com/books?id=NPDgD546-doC&pg=PP1#v=onepage&q&f=false

But can be trimmed to:
: https://books.google.com/?id=NPDgD546-doC&pg=PP1#v=onepage&q&f=false
or:
: https://books.google.com/?id=NPDgD546-doC&printsec=frontcover
or:
: https://books.google.com/?id=NPDgD546-doC (if Google Books does not provide the cover page).

====Pages====
A direct link to a specific page may be used if supported by the host. For example, the link to page 172 of ''Monty Python and Philosophy'' on Google Books:
: https://books.google.com/?id=NPDgD546-doC&pg=PA172
like so:
: <code><nowiki>|page=[https://books.google.com/?id=wPQelKFNA5MC&pg=PA172 172]</nowiki></code>

====Special characters====
{{MediaWiki URL rules}}

====Access date====
* '''access-date''': The full date when the content pointed to by '''url''' was last verified to support the text in the article; do not wikilink; requires '''url'''; use the same format as other access and archive dates in the article's citations.  It is ''not required for linked documents that do not change.'' For example, '''access-date''' is not required for links to copies of published research papers accessed via DOI or a published book, but should be used for links to news articles on commercial websites (these can change from time to time, even if they are also published in a physical medium). Note that '''access-date''' is the date that the URL was checked to not just be working, but to support the assertion being cited (which the current version of the page may not do). Can be [[Help:Citation Style 1/accessdate|hidden or styled]] by registered editors. Alias: '''accessdate'''.