Changes
→Cite uses deprecated parameter |<param>: |deadurl= and |dead-url= are not supported so cannot be deprecated;
==Most common errors==
<!-- Items listed here with ~10k or more -->
* [[#Cite <template> requires %7C<param>=]], ~71k pages* [[#Italic or bold markup not allowed in: %7C<param>=]], ~66k 52k pages
* [[#Citation without a title of any form]], ~32k pages
* [[#Bare URL without a title]], ~24k pages
<section begin=archive_missing_url_help_text />{{help desk}}<span class="error"><code style="color:inherit; border:inherit; padding:inherit;">|archive-url=</code> requires <code style="color:inherit; border:inherit; padding:inherit;">|url=</code></span>
A properly formatted citation that includes {{para|archive-url}} and {{para|archive-date}} requires {{para|url}}. When the citation includes {{para|url-status|live}} or {{para|dead-url|no}}, the ordering of elements in the rendered citation is changed to put the original url first.
To resolve this error, provide a value for {{para|url}}. For web resources archived at archive.org,<ref name="archive.org" /> the original url can be found in the {{para|archive-url}} value; for resources archived at webcitation.org,<ref name="webcitation.org" /> the original url is included in the archive header.
To resolve this error, ensure that the date is an actual date and that the date format follows the [[MOS:DATEFORMAT|Wikipedia Manual of Style's guidance on dates]] in the named parameter. See [[Help:CS1 errors#ExamplesOfUnacceptableDates|examples of unacceptable dates and how to fix them]], below. Or, some conceptual issues to look for:
*impossible dates, such as 29 February 2011(2011 was not a leap year)
* {{para|access-date}} must specify a day, not just a month or year.
*misplaced, incorrect, or extraneous punctuation
*other unacceptable date formats listed in [[MOS:BADDATEFORMAT]]
*more than one date in a date-holding parameter
*Does not handle years before 100 AD, including BCE/BC dates. Try using parameter {{para|orig-year}} instead.
See [[Help:Citation_Style_1#CS1_compliance_with_Wikipedia.27s_Manual_of_Style|Help: Citation Style 1]] for information about limitations in the CS1 citation templates' handling of date formats. [[WP:DATERANGE|The MOS section on date ranges]] describes how to separate dates in a date range. Do not use <code>&nbsp;</code>, <code>&ndash;</code>, or {{tlx|spaced ndash}} as these corrupt the metadata. To add an en dash, use the [[Help:CharInsert#Insert|CharInsert]] edit tool or see [[Wikipedia:How to make dashes]]. You may also use this one: –. A bot is often able to correct the separator, provided the overall format is unambiguous.
<section begin=bad_doi_help_text />{{help desk}}<span class="error">Check <code style="color:inherit; border:inherit; padding:inherit;">|doi=</code> value</span>
When {{cs1}} and {{cs2}} templates contain {{para|doi}}, a test is done to see if the prefix portion of the [[Digital object identifier|DOI]] value contains is correctly formatted and has what appears to be a valid registrant code. A proper doi prefix begins with the proper <code>10.</code> registry identifierdirectory indicator. The remaining portion of the prefix is a string of digits and the dot character which form the registrant code. When the directory indicator is <code>10.</code>, the cs1|2 templates test for a valid registrant code. Valid registrant codes:*must be composed of digits*must be in the range:** 1000–9999** 10000–39999*may have one or more subcodes that begin with a dot followed by digits (1000.10)*must not be 5555 (invalid/temporary/test)Additionally, the {{para|doi}} value is checked to make sure that it does not contain spaces, en dashes, does not end with punctuation, or uses the invalid/temporary/test DOI prefix <code>10.5555</code>. Further validation of the DOI is not performed.
To resolve this error, ensure that the {{para|doi}} value is correct.
!Deprecated parameter!!Replace with
|-
|{{para|class}}|Supported only by {{tlx|cite arXiv}} – remove, or use {{tlx|cite arXiv}} if appropriate.|-|{{para|deadurl}}|rowspan="2"|{{para|url-status}} to one of the following values as appropriate: <code>dead</code>, <code>live</code>, <code>unfit</code>, <code>usurped</code>|-none deprecated at present|{{para|dead-url}}|-|{{para|laysummary}}|rowspan="2"|{{para|lay-url}}|-|{{para|lay-summary}}|-|{{para|registration}}|rowspan="2"|Set one of the following to <code>subscription</code> or <code>registration</code> as appropriate: {{para|url-access}}, {{para|chapter-url-access}}, {{para|entry-url-access}}, {{para|article-url-access}}, {{para|section-url-access}} {{crossref|(detailed documentation [[Help:Citation Style 1#Registration or subscription required|here]])}}.|-|{{para|subscription}}
|}<section end=deprecated_params_table />
<section begin=contributor_ignored_help_text />{{help desk}}<span class="error"><code style="color:inherit; border:inherit; padding:inherit;">{{pipe}}contributor=</code> ignored</span>
Only used in book citations, {{para|contributor}} identifies the author of a contribution, typically an afterword, forwardforeword, introduction, preface, etc., to another (primary) author's work. This error occurs when {{para|contributor}} is used in a template that is not {{tlx|cite book}} or {{tlx|citation}} or is one of these two templates and one of the {{para|work}} parameter aliases is set.
To resolve this error, choose a more appropriate CS1 or CS2 template or remove {{para|contributor}}.
*<span class="error"><code style="color:inherit; border:inherit; padding:inherit;">{{pipe}}contributor=</code> requires <code style="color:inherit; border:inherit; padding:inherit;">{{pipe}}contribution=</code></span></div>
Only used in book citations, {{para|contributor}} identifies the author of a contribution, typically an afterword, forwardforeword, introduction, preface, etc., to another (primary) author's work. As such, the primary author is required ({{para|author}} or appropriate alias) as is the title of the contribution ({{para|contribution}}).
To resolve this error, include the book's primary author in {{para|author1}}, or {{para|last1}}, {{para|first1}}, or {{para|vauthors}} and include the contribution title in {{para|contribution}}; or remove {{para|contributor}}.
|-
!parameter !! acceptable values
|-
|{{para|df}} ||<code>dmy</code>, <code>dmy-all</code>, <code>mdy</code>, <code>mdy-all</code>, <code>ymd</code>, <code>ymd-all</code>