Help:CS1 errors

This page describes the error messages reported by Module:Citation/CS1, what they mean, and suggests how editors might resolve the errors.

In 2013, Wikipedia editors upgraded the Citation Style 1 series of templates using the meta-template {{Citation/core}} into a single Lua module as part of WP:LUA. The benefits of the upgrade are enhanced performance, reduced complexity and redundancy, and for the purposes of this page, improved error detection and reporting.

|accessdate= requires |url=

<section begin=accessdate_missing_url_help_text />

The |accessdate= parameter is used to identify the date that the web resource addressed by |url= was accessed. Without |url=, |accessdate= is meaningless. When |url= is omitted or left blank, the |accessdate= value is not displayed.

To resolve this error, provide a value for |url= or remove |accessdate=.

Pages with this error are automatically placed in Category:Pages using citations with accessdate and no URL.<section end=accessdate_missing_url_help_text />

|archiveurl= and |deadurl=no requires |url=

<section begin=x_help_text />

This error message should probably be removed. |archiveurl= always requires |url= regardless of the state of |deadurl=

Editors often preemptively locate an archived copy of a web resource and include the archive's url in a CS1 citation. When they do, they may set |deadurl=no to indicate that the original source url is still active. |deadurl= controls how the CS1 citation is formatted. Omitted or empty |deadurl= has the same effect as |deadurl=yes.

To resolve this error, provide a value for |url=. For web resources archived at archive.org, the original url can be found in the |archiveurl= value; for resources archived at webcitation.org, the original url is included in the archive header.

Pages with this error are automatically placed in Category:Pages with archiveurl citation errors.<section end=x_help_text />

|archiveurl= requires |archivedate=

<section begin=archive_missing_date_help_text />

|archivedate= identifies the date that the web resource was archived.

To resolve this error, provide a value for |archivedate=. For web resources archived at archive.org, the archival date can be found in the |archiveurl=; for resources archived at webcitation.org, the cache date is included in the archive header.

Pages with this error are automatically placed in Category:Pages with archiveurl citation errors.<section end=archive_missing_date_help_text />

|archiveurl= requires |url=

<section begin=archive_missing_url_help_text />

A properly formatted citation that includes |archiveurl= and |archivedate= requires |url=. When the citation includes |deadurl=no, the ordering of elements in the rendered citation is changed to put the original url first. This error message is not displayed by {{cite web}}.

To resolve this error, provide a value for |url=. For web resources archived at archive.org, the original url can be found in the |archiveurl= value; for resources archived at webcitation.org, the original url is included in the archive header.

Pages with this error are automatically placed in Category:Pages with archiveurl citation errors.<section end=archive_missing_url_help_text />

Bad DOI specified

<section begin=bad_doi_help_text />

When CS1 citations contain |doi=, a test is done to see if the prefix portion of the DOI value contains the proper "10." registry identifier. Further validation of the DOI is not performed.

To resolve this error, ensure that the |doi= value is correct.

Pages with this error are automatically placed in Category:Pages with DOI errors.<section end=bad_doi_help_text />

Bad ISBN specified

<section begin=bad_isbn_help_text />

When CS1 citations contain |isbn=, a test is done to see if the ISBN length and check sum correspond to the ISBN specification. Both 10 digit and 13 digit ISBNs are supported. Further validation of the ISBN is not performed.

To resolve this error, ensure that the |isbn= value is correct.

Pages with this error are automatically placed in Category:Articles with invalid ISBNs.<section end=bad_isbn_help_text />

Bad OL specified

<section begin=bad_ol_help_text />

When CS1 citations contain |ol=, a test is done to see if the last digit of the value is one of three characters: A (authors), M (books), or W (works). Further validation of the OL identifier is not performed.

To resolve this error, ensure that the |ol= value is correct.

Pages with this error are automatically placed in Category:Pages with OL errors.<section end=bad_ol_help_text />

|displayauthors= suggested

<section begin=displayauthors_help_text />

Prior to the introduction of Lua-based citations, the citation formatting templates were designed to support no more than nine authors. If nine (or more) author parameters were specified, then the template would display eight author names followed by "et al." to indicate that the list had been truncated. Some editors relied on this behavior to generate the "et al." labeling. For example:

The Lua-based citation templates can accommodate an arbitrarily large number of authors. As with the old templates, the Lua-based templates can explicitly generate an "et al." with the |display-authors= parameter.

The old-style templates supported at most nine authors. The new Lua-based templates cannot know if editors created citations with exactly nine authors because there were only nine authors or, because old-style citations were limited to nine authors. This error message is reported by citations with exactly nine authors but without |displayauthors=. To preserve the behavior of old-style citations, Lua-based citations display "et al." in place of the ninth author.

To resolve this error, add the remaining authors to the citation or set |displayauthors= to 8 or some lesser value to truncate the author list. If there are exactly nine authors, then set |displayauthors= to 9 or higher to display all nine authors without "et al."

Pages with this error are automatically placed in Category:Pages using citations with old-style implicit et al.<section end=displayauthors_help_text />

|displayeditors= suggested

<section begin=displayeditors_help_text />

Prior to the introduction of Lua-based citations, the citation formatting templates were designed to support no more than four editors. Specifically, if four (or more) editor parameters were specified, then the template would display three editor names followed by "et al." to indicate that the list had been truncated. Some editors relied on this behavior to generate the "et al." labeling. For example:

The Lua-based citation templates can accommodate an arbitrarily large number of editors. The Lua-based templates can also explicitly generate an "et al." with the new |displayeditors= parameter, a parameter that was not available to the old-style templates.

The old-style templates supported at most four editors. The new Lua-based templates cannot know if Wikipedia editors created citations with exactly four editors because there were only four editors or, because old-style citations were limited to four editors. This error message is reported by citations with exactly four editors but without |displayeditors=. To preserve the behavior of old-style citations, Lua-based citations display "et al." in place of the fourth editor.

To resolve this error, add the remaining editors to the citation or set |displayeditors= to 3 or some lesser value to truncate the editor list. If there are exactly four editors, then set |displayeditors= to 4 or higher to display all four editors without including "et al."

Pages with this error are automatically placed in Category:Pages using citations with old-style implicit et al.<section end=displayeditors_help_text />

Empty citation

<section begin=empty_citation_help_text />

"Empty" may mean that the CS1 citation contains no recognizable parameter identifiers. For example this citation isn't "empty" because it contains usable information, but is "empty" because it doesn't contain the necessary parameter identifiers (in this case |url= and |title=) that tell {{cite web}} how to use the information that the citation does contain:

{{cite web | http://www.foobar.com | The Foobar Bar}}

To resolve this error, add appropriate parameter identifiers. Consider the possibility that the editor meant to use another template entirely. Perhaps the editor used {{citation}} when the intent was to use {{citation needed}} or {{quote}}. In these cases replace the CS1 citation with the appropriate template.

Pages with this error are automatically placed in Category:Pages with empty citations.<section end=empty_citation_help_text />

Extra |pages or |at

<section begin=extra_pages_help_text />

This error occurs when CS1 citations attempt to simultaneously use more than one of the parameters: |page=, |pages=, or |at=. Each of these parameters is meant to provide a different way of specifying the location of the cited content within a larger work, and only one of these parameters is displayed in any rendered citation. According to their intended purpose, |page= should be used to specify a single page that is relevant to the cited content, |pages= should be used to specify a range or list of pages (e.g. 37–42) that are relevant, and |at= should be used to indicate a location in the larger work that is not a numbered page (e.g. "back cover"). Sometimes, editors misunderstand the meaning of |pages=, and attempt to use it to indicate the total number of pages in the resource.

When |page= is used with either or both of |pages= or |at=, only the |page= value is displayed. Similarly, when |pages= is used with |at=, only the |pages= value is displayed.

To resolve this error, remove the inappropriate parameter.

Pages with this error are automatically placed in Category:Pages with citations using conflicting page specifications.<section end=extra_pages_help_text />

|format= requires |url=

<section begin=format_missing_url_help_text />

This error occurs when CS1 citations use |format= without also providing a url for |url=. The |format= parameter is used to specify the file format of a web resource (e.g. PDF, DOC, XLS, etc.). In some cases an editor may have intended to use |type= to specify a kind of document (e.g. hard cover, paperback, pamphlet, etc.) The |format= value is always displayed.

To resolve this error, remove |format= or define |url= or change |format= to |type=.

Pages with this error are automatically placed in Category:Pages using citations with format and no URL.<section end=format_missing_url_help_text />

Missing or empty |chapter=

<section begin=trans_missing_chapter_help_text />

This error occurs when a CS1 citation includes an English translation of a chapter title in |trans_chapter= without also including the original language chapter title in |chapter=.

To resolve this error, provide a value for |chapter=. Consider adding |language= if not already part of the citation.

Pages with this error are automatically placed in Category:Pages with citations using translated terms without the original.<section end=trans_missing_chapter_help_text />

Missing or empty |title=

There are four slightly different error conditions that can arise when CS1 citations lack appropriate titles. In each case they report this error message, though the necessary resolution may vary slightly depending on the cause of the error. Help links in the error message link to the appropriate description.

<section begin=citation_missing_title_help_text />

Citation has no title of any form

This error occurs for CS1 citations when all of the associated title parameters are left blank. Depending on the type of citation (e.g. web, book, journal, etc.), the possible title parameters may include |title=, |chapter=, |article=, |journal=, |booktitle=, and so forth. At least one such title parameter must be provided for each citation.

Sometimes this error occurs because an editor has used a CS1 citation as a substitute for {{sfn}} or the {{harv}} family of shortened footnotes.

To resolve this error, provide a value for |title= or, when used as a shortened footnote substitute, replace the CS1 citation with an appropriate shortened footnote template.

Pages with this error are automatically placed in Category:Pages with citations lacking titles.<section end=citation_missing_title_help_text />

<section begin=bare_url_missing_title_help_text />

Bare URL in need of a title

This error message is reported by all Lua-based CS1 citations except {{cite web}} when a URL containing parameter, such as |url=, can not be pairs with an associated title. Because URLs are ugly and generally uninformative, it is expected that editors should provide a meaningful title for each URL. In most cases this can be accomplished by using the |title= parameter. However, this error may also occur with other rarely used URL parameters, such as |chapter-url=, or when the |title= can not be linked due to conflicting |titlelink= parameter.

To resolve this error, provide an appropriate title for the URL, often using |title=.

Pages with this error are automatically placed in Category:Pages with citations having bare URLs.<section end=bare_url_missing_title_help_text />

<section begin=cite_web_title_help_text />

Web citation with no title

This error message is generated only by {{cite web}} citations that use |url= without an associated |title=. Because URLs are ugly and generally uninformative, it is expected that editors should provide a meaningful title for each URL. When rendered these citations display the bare URL followed by the error message .

To resolve this error, provide a value for |title=.

Pages with this error are automatically placed in Category:Pages using web citations with no title.<section end=cite_web_title_help_text />

<section begin=trans_missing_title_help_text />

Translated title included without the original

This error occurs when a CS1 citation includes an English translation of the title in |trans_title= without also including the original language title in |title=.

To resolve this error, provide a value for |title=. Consider adding |language= if not already part of the citation.

Pages with this error are automatically placed in Category:Pages with citations using translated terms without the original.<section end=trans_missing_title_help_text />

Missing or empty |url=

<section begin=cite_web_url_help_text />

This is error message is reported only by {{cite web}} CS1 citations where |url= is blank or omitted. The |url= parameter is required so that |title= can link to the web resource.

To resolve this error, provide a value for |url= or use a more appropriate CS1 citation.

Pages with this error are automatically placed in Category:Pages using web citations with no URL.<section end=cite_web_url_help_text />

More than one of |param1=, |param2=, and |param3= specified

<section begin=redundant_parameters_help_text />

This error occurs when a CS1 citation includes more than one parameter that maps to the same meaning. For example, |author=, |last=, and |last1= are all synonyms of each other, and so no more than one of these parameters should ever be used in a single citation.

To resolve this error, remove or modify the redundant parameter(s).

Pages with this error are automatically placed in Category:Pages with citations having redundant parameters.<section end=redundant_parameters_help_text />

Text "????" ignored

<section begin=text_ignored_help_text />

Unlike many Wikipedia templates, the CS1 citations do not use unnamed or positional parameters. When a citation contains text between vertical bars and that text does not contain an equal sign (=), the text is ignored and an error message generated. This is true even when the text is the name of a valid parameter.

This error can also caused by vertical bars that are part of urls or titles. When vertical bars occur in urls, replace each vertical bar with %7c. When vertical bars occur in parameter values that are not urls, replace each vertical bar with |.

To resolve this error, remove the extraneous text, add '=', add an appropriate parameter name to complete the parameter, or properly encode vertical bars in urls and titles.

Pages with this error are automatically placed in Category:Pages with citations using unnamed parameters.<section end=text_ignored_help_text />

Unknown parameter |????= ignored

<section begin=parameter_ignored_help_text />

This error message is reported by CS1 citations when the name portion of a parameter's |name=value pair is not recognized as a valid name. Typically this is caused by spelling or typographical errors.

To resolve this error, ensure that the parameter's name is correctly spelled and that there are no characters other than spaces between the parameter's name and the leading vertical bar (|) or the trailing equal sign (=). A list of valid parameters can be found by consulting Help:Citation Style 1 or visiting the description page of the specific template being used, such as {{cite web}}, {{cite book}}, {{cite journal}}, etc.

For frequently encountered errors, one may want to add a suggested correction to the suggestion list.

Pages with this error are automatically placed in Category:Pages with citations using unsupported parameters.<section end=parameter_ignored_help_text />

Unknown parameter |xxxx= ignored (|yyyy= suggested)

<section begin=parameter_case_help_text />

This error message is generated by CS1 citations when the name portion of a parameter's |name=value pair is not recognized as a valid name, but the software is also able to suggest an alternative parameter name that may have been intended. Often this occurs because the specified name is capitalized when the citation is expecting the parameter name to use lowercase. With very few exceptions CS1 citation parameters are lower case. Some, like |isbn= can be either lower or upper, but not of mixed case (|isbn= or |ISBN= but not |Isbn=). Alternatively, the citation template may suggest an alternative for frequently encountered errors in spelling or naming based on this suggestion list.

To resolve this error, replace the erroneous parameter name with a correct one, possibly using the suggested name.

Pages with this error are automatically placed in Category:Pages with citations using unsupported parameters.<section end=parameter_case_help_text />

Wikilink embedded in URL title

<section begin=wikilink_in_url_help_text />

This error message is reported by CS1 citations that have wikilinks embedded in |title=, |chapter=, |article=, or |booktitle=, etc. while also specifying a url for that element.

Prior to the 2013 Lua upgrade to the CS1 citations, the templates would simply wrap a URL around a wikilink in |title= which causes the url description to end abruptly at the start of the wikilink, for example:

|url=http://www.foobar.com

|title=The [[Foobar]] Bar

was converted to:

[http://www.foobar.com The [[Foobar]] Bar]

giving the result:

The Foobar Bar.

Following the Lua upgrade to the CS1 citations, brackets appearing within |title= are treated as literal characters, not as wikilink delimiters. The above |url= / |title= example now gives this result:

The [[Foobar]] Bar

To resolve this error, remove wikilinks that occur within parameters that are intended to be externally linked. Alternatively, remove the external url, which will allow the internal wikilinks to work as expected.

Pages with this error are automatically placed in Category:Pages with citations having wikilinks embedded in URL titles.<section end=wikilink_in_url_help_text />