This page describes the error messages reported by the Citation Style 1 and Citation Style 2 citations, what they mean, and how editors might resolve the errors. Category:CS1 errors is the general errors category and Category:CS1 maintenance is the general maintenance category.
Errors issued by Wikipedia’s <ref> system, in which citation templates are typically embedded, can be found at Help:Cite errors.
Controlling error message display
Error and maintenance messages
By default, Citation Style 1 and Citation Style 2 error messages are visible to all readers and maintenance messages are hidden from all readers.
To display maintenance messages, include the following text in your common CSS page or your specific skin’s CSS page (common.css and skin.css respectively):
.mw-parser-output span.cs1-maint {display: inline;} /* display Citation Style 1 maintenance messages */
To display hidden-by-default error messages:
.mw-parser-output span.cs1-hidden-error {display: inline;} /* display hidden Citation Style 1 error messages */
Even with this CSS installed, older pages in Wikipedia’s cache may not have been updated to show these error messages even though the page is listed in one of the tracking categories. A null edit will resolve that issue.
To hide normally-displayed error messages:
.mw-parser-output span.cs1-visible-error {display: none;} /* hide Citation Style 1 error messages */
You can personalize the display of these messages (such as changing the color), but you will need to ask someone who knows CSS or at the technical village pump if you do not understand how.
Properties category highlighting
Module:Citation/CS1 adds properties categories to some CS1|2 citations. Unlike errors or maintenance needs, there is no message when a properties category is added. Properties categories may be temporary or may be perpetual. Editors can use CSS to add special styling to CS1|2 template renderings that will highlight a citation that added a properties category. For example, this template uses a long volume name:
{{cite book |title=Title |date=May–Jun 2021 |volume = 1: Long volume}}- Title. Vol. 1: Long volume. May–Jun 2021.
If you add this to your CSS that citation will render with a pale yellow background:
.cs1-prop-long-vol {background: #FFC;}
Add one or more of these (with appropriate styling) to your CSS to highlight template renderings when when those templates add the associated properties category:
.cs1-prop-foreign-lang-source {}– subcategories of Category:CS1 foreign language sources.cs1-prop-foreign-lang-source-2 {}– Category:CS1 foreign language sources (ISO 639-2).cs1-prop-jul-greg-uncertainty {}– Category:CS1: Julian–Gregorian uncertainty.cs1-prop-location-test {}– Category:CS1 location test.cs1-prop-long-vol {}– Category:CS1: long volume value.cs1-prop-script {}– subcategories of Category:CS1 uses foreign language script.cs1-prop-tracked-param {}– subcategories of Category:CS1 tracked parameters.cs1-prop-year-range-abbreviated {}– Category:CS1: abbreviated year range
Most common errors
- #Citation without a title of any form, ~35k pages
- #Cite uses generic name, ~30k pages
- #Bare URL without a title, ~24k pages
- See also: Category:CS1 errors and Category:CS1 maintenance
|access-date= requires |url=
|access-date= requires |url=
The |access-date= is the date that the online resource addressed by |url= was added to the article. If |access-date= has been included in the citation without |url= then this message appears. If the citation does not use a web link, then |access-date= is redundant and should be removed.
When the online resource has a publication or other fixed date associated with it, |access-date= is of limited value though may be useful in identifying an appropriate archived version of the resource. Without |url=, |access-date= is not considered useful.
To resolve this error, provide a value for |url= or remove |access-date=. Editors should try to determine why the citation has |access-date= without |url=. For example, the citation may never have had a |url=, or |url= may have been removed because it links to a site that violates the creator’s copyright (see WP:COPYLINK), or because |url= was deemed to be dead. If the citation never had |url= or it was removed for copyright violations, remove |access-date=. When a dead |url= has been removed, restore the |url= and if possible repair it (see WP:LINKROT).
Pages with this error are automatically placed in Category:CS1 errors: access-date without URL (1,471 pages).[a]
|archive-url= is malformed
|archive-url= is malformed: <reason>
Archive.org allows a variety of URLs to access snapshots of an archived page. Some of these are:
https://web.archive.org/web/YYYYMMDD– a single snapshot; this is the preferred form for use withhhmmss/http://www.example.com |archive-url=https://web.archive.org/web/*/http://– a wildcard search results page; useful for locating an appropriate snapshot but not appropriate in a citationwww.example.com https://web.archive.org/web/– incomplete timestamp; archive.org returns the most recent snapshot201603/http://www.example.com https://web.archive.org/save/http://– saves a new snapshot of the current target; do not use this formwww.example.com
There are two forms of the basic URL:
https://web.archive.org/<timestamp>/...– the old formhttps://web.archive.org/web/<timestamp><flags>/...– the new form
The error message identifies the reason for the message. The reasons are:
- save command – the archive.org URL is the save command
- path – web/ was expected but something else was found
- timestamp – the timestamp portion of the URL path is not 14 digits
- flag – the flag portion of the URL path (if present; new form URLs only) is not 2 lowercase letters followed by an underscore: ‘id_’
- liveweb –
liveweb.archive.orgis a deprecated form of the domain name
When the archive.org URL has any of these errors, Module:Citation/CS1 does not link to archive.org in normal article view and emits an appropriate error message.
However, in article preview mode, the module creates a modified link to archive.org that uses a partial timestamp with * wildcard suffix. This new URL links to an archive.org calendar view so that editors may more easily select a suitable archived snapshot from those available at archive.org to fix the malformed |archive-url= link. (If no snapshots have been archived at archive.org, and the cited page is still live, this link also allows editors to save the first snapshot of the page at archive.org.)
To resolve this error, choose the URL of an appropriate snapshot from those held at archive.org. Search for the target URL at archive.org.
Pages with this error are automatically placed in Category:CS1 errors: archive-url (106 pages).[a]
|archive-url= requires |archive-date=
|archive-url= requires |archive-date=
|archive-date=, identifies the date that the web resource was archived.
To resolve this error, provide a value for |archive-date= (see acceptable date formats in MOS:DATEFORMAT). For web resources archived at archive.org,[1] the archival date can be found in the |archive-url=; for resources archived at webcitation.org,[2] the cache date is included in the archive header.
Pages with this error are automatically placed in Category:CS1 errors: archive-url (106 pages).[a]
|archive-url= requires |url=
|archive-url= requires |url=
A properly formatted citation that includes |archive-url= and |archive-date= requires |url=. When the citation includes |url-status=live, the ordering of elements in the rendered citation is changed to put the original URL first.
To resolve this error, provide a value for |url=. For web resources archived at archive.org,[1] the original URL can be found in the |archive-url= value; for resources archived at webcitation.org,[2] the original URL is included in the archive header.
Pages with this error are automatically placed in Category:CS1 errors: archive-url (106 pages).[a]
|arxiv= required
|arxiv= required
{{cite arXiv}} requires one, but not both, of the identifier parameters |arxiv= or |eprint= to specify an arXiv identifier.
To resolve this error, ensure that the template has |arxiv= or |eprint= with a properly constructed value.
Pages with this error are automatically placed in Category:CS1 errors: arXiv (1 page).[a]
|asin-tld= requires |asin=
|asin-tld= requires |asin=
When |asin-tld= is used in a CS1|2 template, |asin= (with value) must also be present.
To resolve this error, either add the missing ASIN or remove the ‘broken’ parameter.
Pages with this error are automatically placed in Category:CS1 errors: ASIN TLD (0 pages).[a]
|biorxiv= required
|biorxiv= required
{{cite bioRxiv}} requires the identifier parameter |biorxiv=.
To resolve this error, ensure that the template has |biorxiv= with a properly constructed value.
Pages with this error are automatically placed in Category:CS1 errors: bioRxiv (0 pages).[a]
|chapter= ignored
|chapter= ignored
Citation Style 1 templates {{cite web}}, {{cite news}}, {{cite journal}}, {{cite press release}}, {{cite podcast}}, {{cite newsgroup}}, as well as template {{citation}} when it uses |work= or any of its aliases, do not support |chapter= or the aliases |contribution=, |entry=, |article=, or |section=.
To resolve this error:
- use a more appropriate citation template, or
- place the content of the
|chapter=parameter in|title=, or - for {{cite news}},
|department=can be used to give the name of the newspaper’s section, such as “Obituaries”, or - for {{citation}}, remove
|work=or its aliases such as|website=and place their content in|title=if appropriate
Pages with this error are automatically placed in Category:CS1 errors: chapter ignored (1 page).[a]
<char> character in |<param>= at position n
Help desk
<char> character in |<param>= at position n
This error is reported for citations with parameter values that contain invisible or non-printable characters known as control characters; the error includes the position at which the character can be found. Module:Citation/CS1 detects parameter values that contain any of these characters:
- non-breaking space, U+00A0
- soft hyphen, U+00AD
- replacement character, U+FFFD
- hair space, U+200A
- zero-width space, U+200B
- zero-width joiner, U+200D
- horizontal tab, U+0009 (HT)
- line feed, U+0010 (LF)
- carriage return, U+0013 (CR)
- delete character, U+007F (DEL)
- C0 control, U+0000–U+001F (NULL–US)
- C1 control, U+0080–U+009F (XXX–APC)
To resolve invisible-character errors, remove or replace the identified character. Most intentional white-space characters should be replaced with a normal space character (i.e. press your keyboard’s space bar). See MOS:NBSP for guidance on insertion of intentional non-breaking spaces.
Because these characters are mostly invisible, the error message identifies the character’s position in the parameter value counted from the left. Space characters between the assignment operator (the ‘=’ sign) and the parameter value are not counted. If you move through the citation with the arrow keys then the cursor may stand still once at an invisible character, which can be removed with Delete or ← Backspace. If you copy-paste a string to the “Characters” field at https://r12a.github.io/app-conversion/ and click “View in UniView” then the position and name of all characters is shown.
<name> stripmarker in |<param>= at position n
Strip markers are special sequences of characters that MediaWiki inserts as a place-holder for certain XML-like tags. These tags include <gallery>...</gallery>, <math>...</math>, <nowiki>...</nowiki>, <pre>...</pre>, and <ref>...</ref>. The strip markers are replaced with content before the final page rendering. The module ignores math and nowiki strip markers.
To resolve strip marker errors, remove or replace the identified tag. The error message identifies the strip marker’s position in the parameter value counted from the left. Space characters between the assignment operator (the ‘=’ sign) and the parameter value are not counted when calculating the position.
Strip marker errors can also be caused by unsupported additional text or templates in parameter values—for example, {{ISBN}} in |title=. Resolve the problem by moving the extraneous text outside the citation template, or by removing the extraneous text or template markup, as appropriate.
Pages with this error are automatically placed in Category:CS1 errors: invisible characters (3 pages).[a]
Check |arxiv= value
Check |arxiv= value
When Citation Style 1 and Citation Style 2 templates contain |arxiv=, a test is done to see if the arXiv identifier conforms with the arXiv identifier scheme.[3] The identifier is checked for a valid number of digits in the article id; valid year and month values; and properly-placed hyphens, slashes, and dots.
To resolve this error, ensure that the |arxiv= value is correct.
Pages with this error are automatically placed in Category:CS1 errors: arXiv (1 page).[a]
Check |asin= value
Check |asin= value
When Citation Style 1 and Citation Style 2 templates contain |asin=, a test is done to see if the ASIN identifier contains ten upper-case alphanumeric characters without punctuation or spaces and that if the first character is numeric, that the ASIN conforms to the rules for a ten-digit ISBN.
To resolve this error, ensure that the |asin= value is correct.
If the |asin= value is correct and all-numeric, use |isbn= instead and delete any |asin-tld= parameters. Articles with CS1 citations that use |asin= with all numeric values are categorized in Category:CS1 maint: ASIN uses ISBN.
Pages with this error are automatically placed in Category:CS1 errors: ASIN (0 pages).[a]
Check |asin-tld= value
Check |asin-tld= value
Citation Style 1 and Citation Style 2 templates contain a test for known |asin-tld= values to specify the top-level domain (TLD) of a given ASIN identifier link. The list of currently supported values is:
ae, au, br, ca, cn, de, es, fr, in, it, jp, mx, nl, pl, sa, se, sg, tr, uk
It is not necessary to provide |asin-tld= to specify the default (United States). If you want to specify this condition explicitly, a pseudo-value of us can be given to denote this.
All these values are automatically resolved to the correct TLD following one of the schemes nn, com.nn, co.nn, z.nn, and com.
If an unsupported value is encountered, the template will issue this error message.
To resolve this error, ensure that the |asin-tld= value is correct.
If the value is correct, please report this at Help talk:Citation Style 1, so that it can be added to the list of supported values.
Pages with this error are automatically placed in Category:CS1 errors: ASIN TLD (0 pages).[a]
Check |bibcode= <message> Help desk
Check |bibcode= <message>
When Citation Style 1 and Citation Style 2 templates contain |bibcode=, a test is done to see if the bibcode identifier has the proper format.[4] Bibcodes are expected to match these requirements:
- length must be 19 characters (<message> = ‘length‘)
- characters in position(s): (except as specified otherwise, violations produce ‘value‘ in the <message> portion of the error message):
- 1–4 must be digits and must represent a year in the range of 1000 – next year (<message> = ‘year‘)
- 5 must be a letter
- 6–8 must be a letter, ampersand, or dot (ampersand cannot directly precede a dot; &. (<message> = ‘journal‘))
- 9 must be a letter or dot
- 10–18 must be a letter, digit, or dot
- 19 must be a letter or dot
To resolve this error, ensure that the |bibcode= value is correct.
Pages with this error are automatically placed in Category:CS1 errors: bibcode (1 page).[a]
Check |biorxiv= value
Check |biorxiv= value
When Citation Style 1 and Citation Style 2 templates contain |biorxiv=, a test is done to see if the bioRxiv identifier has the proper form. There are two valid forms, each beginning with bioRxiv’s doi directory indicator and registrant code (10.1101) and followed by:
- six numeric characters without punctuation or spaces:
|biorxiv=10.1101/############– 6-digit bioRxiv identifier
- ymd format date prefix followed by six numeric characters without punctuation or spaces followed by optional version:
|biorxiv=10.1101/yyyy.mm.dd.######v#where:yyyy.mm.dd.– represents a date no earlier than 11 December 2019 (2019.12.11.) and no later than tomorrow’s date; date must be a valid date######– 6-digit bioRxiv identifierv#– optional version indicator
A common error is to include the bioRxiv URL (https://dx.doi.org/10.1101/######}}).
To resolve this error, ensure that the |biorxiv= value is correct.
Pages with this error are automatically placed in Category:CS1 errors: bioRxiv (0 pages).[a]
Check |citeseerx= value
Check |citeseerx= value
When Citation Style 1 and Citation Style 2 templates contain |citeseerx=, a test is done to see if the CiteSeerX identifier has the proper format.
The expected identifier is the value assigned to the ?doi= query key in the URL of a CiteSeerX document. (This query key should not be confused with a Digital Object Identifier: it should not be input as |doi=.)
For instance, if you want to link to http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.220.7880, use |citeseerx=10.1.1.220.7880.
Pages with this error are automatically placed in Category:CS1 errors: citeseerx (0 pages).[a]
Check date values in: |<param1>=, |<param2>=, … Help desk
- Check date values in:
|<param1>=,|<param2>=, … - Check date values in:
|year=/|date=mismatch
When Citation Style 1 and Citation Style 2 templates contain date-holding parameters, an automated test is done to see if the dates are real dates that comply with a subset of the date rules in Wikipedia’s Manual of Style, specifically checking for violations of MOS:DATEFORMAT.
To resolve this error, ensure that the date is an actual date and that the date format follows the Wikipedia Manual of Style’s guidance on dates in the named parameter. See 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)
|access-date=must specify a day, not just a month or year.- misplaced, incorrect, or extraneous punctuation
- extraneous text
- hyphens or slashes instead of en dashes in date ranges (en dashes are required)
- misspelling or improper capitalization (see MOS:ALLCAPS for more detail that is not in Wikipedia Manual of Style’s guidance on dates)
- other unacceptable date formats listed in MOS:BADDATEFORMAT
- more than one date in a date-holding parameter
- years before 100 AD, including BCE/BC dates. Try using parameter
|orig-date=instead.
See Help: Citation Style 1 for information about limitations in the CS1 citation templates’ handling of date formats. The MOS section on date ranges describes how to separate dates in a date range. Do not use , –, or {{spaced ndash}} as these corrupt the metadata. To add an en dash, use the CharInsert edit tool or see Wikipedia:How to make dashes. You may also copy and paste this one: –. A bot is often able to correct the separator, provided the overall format is unambiguous.
Future dates in |date= in CS1|2 citations are limited to current year + 1; that is, for 2022, citation dates in 2023 are acceptable but citation dates in 2024 and beyond are not.
Dates prior to 1582 are treated as Julian calendar dates. Dates from 1582 onward are treated as Gregorian calendar dates. The Julian calendar was used in some places until approximately 1923. Three Julian calendar dates in the overlap period, 29 February in the years 1700, 1800, and 1900, will cause this error message because those years are not leap years in the Gregorian calendar.
The access date (in |access-date=) is checked to ensure that it contains a full date (day, month, and year) and is between 15 January 2001 (the founding date of Wikipedia) and today’s date plus one day, because it represents the date that an editor viewed a web-based source to verify a statement on Wikipedia. Because editors may be in time zones that are one day ahead of the UTC date, one extra day is accepted.
Pages with this error are automatically placed in Category:CS1 errors: dates (6,459 pages).[a]
| Issue | Unacceptable | Acceptable |
|---|---|---|
| Hyphen in date range (use en dash) | |date=2002-2003 |
|date=2002–2003
|
| Slash in date range (use en dash) | |date=2002/2003 or |date=July/August 2003 |
|date=2002–2003 or |date=July–August 2003
|
| Hyphen in date range (use en dash) | |date=April-May 2004 |
|date=April–May 2004
|
| Missing space around en dash for range of full dates | |date=April 2003–May 2004 |
|date=April 2003 – May 2004
|
| Month capitalization | |date=28 february 1900 |
|date=28 February 1900
|
| Month capitalization | |date=28 FEBRUARY 1900 |
|date=28 February 1900
|
| Season capitalization | |date=spring 2011 |
|date=Spring 2011
|
| Future date (typo) | |date=2102 |
|date=2012
|
| Access date in future (see note above) | |access-date=May 1, 2022 |
|access-date=April 29, 2022
|
| Access date impossibly far in the past (typo) | |access-date=1 January 2001 |
|access-date=1 January 2010
|
| Access date only specifies month | |access-date=January 2015 |
|access-date=12 January 2015
|
| Ambiguous date range or year and month | |date=2002-03 |
|
| Bad abbreviation | |date=Febr. 28, 1900 |
|
| Nonexistent date | |date=February 29, 1900 |
|
| Undated | |date=Undated |
|date=n.d.
|
| Comma in month and year | |date=February, 1900 |
|date=February 1900
|
| Comma in season | |date=Winter, 1900–1901 |
|date=Winter 1900–1901
|
| Missing comma in format which requires it | |date=February 28 1900 |
|date=February 28, 1900 or |date=28 February 1900 or |date=1900-02-28
|
| Non-date text | |date=2008, originally 2000 |
|date=2008 |orig-date=2000
|
| Zero-padding | |date=January 04, 1987 |
|date=January 4, 1987
|
| Date with slashes | |date=12/6/87 |
|date=December 6, 1987 or |date=6 December 1987 or |date=1987-12-06or |date=12 June 1987 or |date=June 12, 1987 or |date=1987-06-12
|
| Two-digit year | |date=87-12-06 |
|date=1987-12-06
|
| One-digit month or day | |date=2007-3-6 |
|date=2007-03-06
|
| Wikified date | |date=[[April 1]], [[1999]] |
|date=April 1, 1999
|
| “mm-dd-yyyy” or “dd-mm-yyyy” date format | |date=07-12-2009 |
|date=7 December 2009 or |date=12 July 2009or |date=July 12, 2009 or |date=December 7, 2009or |date=2009-07-12 or |date=2009-12-07
|
| Quarters | |date=3Q 1984 or |date=3rd Qtr., 1984 or |date=Third quarter 1984 |
|date=Third Quarter 1984
|
| Named dates | |date=Xmas 1984 or |date=christmas 1984 |
|date=Christmas 1984
|
| Approximate or uncertain dates | |date=circa 1970 or |date={{circa}} 1970 |
|date=c. 1970
|
Check |doi= value
Check |doi= value
When Citation Style 1 and Citation Style 2 templates contain |doi=, a test is done to see if the prefix portion of the DOI value is correctly formatted and has what appears to be a valid registrant code. A proper DOI prefix begins with the 10. directory 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 10., 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
- 10000–49999
- 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 |doi= value is checked to make sure that it does not contain spaces, en dashes, does not end with punctuation. Further validation of the DOI is not performed.
Do not include the https://doi.org/ scheme and domain name from a URL. A proper |doi= value looks like |doi=10.1103/PhysRevLett.80.904.
To resolve this error, ensure that the |doi= value is correct.
In very rare cases, publishers have released works with a DOI deviating from the standard form. If you are certain that such a non-conforming DOI truly corresponds to the published work, then you can add accept-this-as-written markup around the identifier to suppress the error message. (Do not use this markup for DOIs, which are inactive rather than non-conforming. Instead, use |doi-broken-date= for them.)
Pages with this error are automatically placed in Category:CS1 errors: DOI (13 pages).[a]
Check |hdl= value
Check |hdl= value
When Citation Style 1 and Citation Style 2 templates contain |hdl=, a test is done to see if the hdl value looks like a properly defined value. The |hdl= value is checked to make sure that it does not contain spaces or en dashes and does not end with punctuation. Further validation of the hdl is not performed.
To resolve this error, ensure that the |hdl= value is correct.
Pages with this error are automatically placed in Category:CS1 errors: HDL (0 pages).[a]
Check |isbn= value
Check |isbn= value: <type>
Citation Style 1 and Citation Style 2 templates that contain |isbn= are checked to ensure that the ISBN is the proper length (ten or thirteen digits), that the ISBN uses the correct optional separators (simple space or hyphen), and that the final check digit is correct according to the ISBN specification. Only one ISBN is allowed in this field because the whole |isbn= value is included in the citation’s COinS metadata. See also Wikipedia:COinS. More than one ISBN, or characters that are not part of the ISBN, corrupt the COinS metadata and may also corrupt the link to Special:BookSources. (If relevant, they can be specified using |id={{ISBN|...}} instead.)
The error message <type> indicator can be:
- length – ISBN is not 10 or 13 digits
- checksum – ISBN has one or more incorrect digits; look for typos and transposition
- invalid character – ISBN has one or more ‘digits’ that is not in the allowed set appropriate to ISBN length
- invalid prefix – 13-digit ISBNs must begin with ‘978’ or ‘979’
- invalid form – 10-digit ISBNs with the mis-positioned ‘X’ character
- invalid group id – 13-digit ISBN begins with ‘9790’; this prefix / group ID combination is reserved to ISMN
To resolve this error, ensure that the |isbn= value is correct, that only one ISBN is used, that the proper optional separators are used, and that no other text is included. Use the ISBN printed on the work rather than one retrieved from third-party sources. If both are available, use the 13-digit ISBN.. When a 10-digit ISBN is used, if the check digit is a lowercase ‘x’, change it to an uppercase ‘X’.
- Do not try to resolve the error by simply recalculating the check digit. The check digit is there to check whether the main part of the number is correct. If the ISBN is failing to validate, it is likely that there is a typo in the main part of the number. In this case, recalculating the check digit results in an apparently valid ISBN that leads to the wrong source (or to nowhere).
- If you only have a 10-digit ISBN, do use the number as-is, do not try to convert it to the 13-digit form.
- If the ISBN as printed in your source is refusing to validate, do check both the front matter and the book cover for ISBNs. It is not uncommon for the ISBN to be misprinted in the front matter but correct on the cover.
- Do preview your edit and check that the new ISBN does now link to the correct source.
In very rare cases, publishers have released books with malformed ISBNs. If you are certain that a non-conforming ISBN truly corresponds to the published work, then you can add accept-this-as-written markup around the identifier to suppress the error message. In many cases, books may have been reissued with a corrected ISBN. Use a corrected ISBN when possible.
Sometimes there are numbers assigned to |isbn= that appear to be legitimate – length is right, check digit is correct – but that aren’t true ISBN numbers. This tool may be helpful.
See also Wikipedia:ISBN.
Pages with this error are automatically placed in Category:CS1 errors: ISBN (317 pages).[a]
Check |ismn= value
Check |ismn= value
Citation Style 1 and Citation Style 2 templates that contain |ismn= are checked to ensure that the ISMN is the proper length (thirteen digits), that the ISMN uses the correct optional separators (simple space or hyphen), and that the final check digit is correct according to the ISMN specification. Only one ISMN is allowed in this field because the whole |ismn= value is included in the citation’s COinS metadata. See also Wikipedia:COinS. More than one ISMN, or characters that are not part of the ISMN, corrupt the COinS metadata. (If relevant, they can be specified using |id={{ISMN|...}} instead.)
To resolve this error, ensure that the |ismn= value is correct, that only one ISMN is used, that the proper optional separators are used, and that no other text is included. Make sure that the ISMN contains exactly 13 digits.
Pages with this error are automatically placed in Category:CS1 errors: ISMN (0 pages).[a]
Check |issn= value
- Check
|issn=value - Check
|eissn=value
Citation Style 1 and Citation Style 2 templates that contain |issn= and/or |eissn= are checked to ensure that the ISSN is the proper length (eight digits) and that the final check digit validates according to the ISSN specification. Only one each of ISSN and eISSN is allowed in this field because the whole |issn= and |eissn= values are included in the citation’s COinS metadata. See also Wikipedia:COinS. (If relevant, they can be specified using |id={{ISSN|...}} {{EISSN|...}} instead.)
The ISSN and eISSN are always rendered as two four-digit numbers separated with a hyphen.
To resolve this error, ensure that the |issn= and |eissn= values are correct, that only one value per parameter is used, and that no other text is included (allowable characters are 0–9, X, and -). If the check-digit is a lowercase ‘x’, change it to an uppercase ‘X’. It may also be worth checking an actual hyphen (-) has been used, and not a hyphen-like character like an endash (–).
In very rare cases, publishers have released works with a malformed identifier. If you are certain that a non-conforming identifier truly corresponds to the published work, then you can add accept-this-as-written markup around the identifier to suppress the error message. In some cases, works may have been reissued with a corrected identifier. Use the corrected one when possible.
Pages with this error are automatically placed in Category:CS1 errors: ISSN (18 pages).[a]
Check |jfm= value
Check |jfm= value
When Citation Style 1 and Citation Style 2 templates contain |jfm=, a test is done to see if the JFM identifier value looks like a properly defined value. The |jfm= identifier is checked to make sure that it has the form: nn.nnnn.nn where n is any digit 0–9. Further validation of the JFM identifier is not performed.
To resolve this error, ensure that the |jfm= value is correct.
Pages with this error are automatically placed in Category:CS1 errors: JFM (0 pages).[a]
Check |jstor= value
Check |jstor= value
When Citation Style 1 and Citation Style 2 templates contain |jstor=, a test is done to see if the JSTOR identifier value looks like a properly defined value. Error messages are emitted when the assigned value has some form of the string ‘jstor’ (case-agnostic), or has a URI scheme (http:// or https://), or has any space characters.
To resolve this error, ensure that the |jstor= value is correct.
Pages with this error are automatically placed in Category:CS1 errors: JSTOR (0 pages).[a]
Check |lccn= value
Check |lccn= value
The |lccn= parameter is for the Library of Congress Control Number identifier. It is checked to ensure that the identifier is the proper length and has the correct initial digits.
LCCN is a character string 8–12 characters long. The length of the LCCN dictates the character type of the initial 1–3 characters; the rightmost eight are always digits.[5]
| Length | Description |
|---|---|
| 8 | all characters are digits |
| 9 | first character is a lower case letter |
| 10 | first two characters are either both lower case letters or both digits |
| 11 | first character is a lower case letter, second and third characters are either both lower case letters or both digits |
| 12 | first two characters are both lower case letters |
Further validation is not performed.
To resolve this error, ensure that the |lccn= value is correct and that there are no other letters, punctuation, or other characters.
When receiving this error, be on the lookout for publishers who omitted leading zeros in the LCCN following the two or four digit year. For example, an LCCN that is properly 92-035427 could be shortened in the printed work to 92-35247. When experimenting with inserting omitted zeroes, cross-check the finished number against the LCCN permalinks online.
Pages with this error are automatically placed in Category:CS1 errors: LCCN (1 page).[a]
Check |message-id= value
Check |message-id= value
The |message-id= parameter holds the unique identifier associated with a netnews message.[6] The value in |message-id= is checked to make sure that it contains @ between left and right identifiers. |message-id= is also checked to make sure that the first character is not < and the last character is not >. Module:Citation/CS1 adds the URI scheme news: to the value in |message-id=. If the value in |message-id= is wrapped in <...> characters, the link created fails.
Further validation is not performed.
To resolve this error, ensure that the |message-id= value is correct, that it contains @ and is not wrapped in <...> characters.
Pages with this error are automatically placed in Category:CS1 errors: message-id (0 pages).[a]
Check |mr= value
Check |mr= value
When Citation Style 1 and Citation Style 2 templates contain |mr=, a test is done to see if the MR identifier value looks like a properly defined value. The |mr= identifier is checked to make sure that it contains only digits and that it is no more than seven digits in length. Further validation of the MR identifier is not performed.
To resolve this error, ensure that the |mr= value is correct.
Pages with this error are automatically placed in Category:CS1 errors: MR (0 pages).[a]
Check |oclc= value
Check |oclc= value
The |oclc= parameter is for the OCLC identifier. Only a single OCLC identifier is allowed. (If relevant, multiple OCLCs can be specified using |id={{OCLC|...}} instead.)
The identifier must be in one of these forms:
- prefix
ocmfollowed by 8 digits - prefix
ocnfollowed by 9 digits - prefix
onfollowed by 10 (or more) digits - prefix
(OCoLC)followed by a variable number of digits without leading zeros - 1 to 10 (or more) digits without prefix
Further validation is not performed.
To resolve this error, ensure that the |oclc= value is correct.
If the value is correct and larger than the currently configured limit of 9999999999, please report this at Help talk:Citation Style 1, so that the limit can be updated.
A tip for fixing this error: Editors sometimes place valid ISBN, LCCN, ASIN, or other identifiers in |oclc=.
Pages with this error are automatically placed in Category:CS1 errors: OCLC (1 page).[a]
Check |ol= value
Check |ol= value
The |ol= parameter is for the Open Library identifier. The identifier is one or more digits followed by a last character that is either A (authors), M (books), or W (works). Further validation is not performed.
To resolve this error, ensure that the |ol= value is correct. Do not include “OL” in the value.
Pages with this error are automatically placed in Category:CS1 errors: OL (0 pages).[a]
Check |osti= value
Check |osti= value
The |osti= parameter is for the Office of Scientific and Technical Information (OSTI) identifier. OSTIs are checked to ensure that the identifier is a simple number without punctuation or spaces with a value between 1018 and 23000000. Further validation is not performed.
A common error is to include the OSTI URL (https://dx.doi.org/10.2172/<OSTI>), or the OSTI DOI (10.2172/<OSTI>).
To resolve this error, ensure that the |osti= value is correct.
If the value is correct and lower than 1018 or larger than the currently configured limit of 23000000, please report this at Help talk:Citation Style 1, so that the limit can be updated.
Pages with this error are automatically placed in Category:CS1 errors: OSTI (0 pages).[a]
Check |<param>-link= value Help desk
- Check
|value<param>-link= - Check
|value<param>=
These link-holding parameters and their matching title-/name-holding parameters are combined to create a working wikilink to a related article.
| Link-holding parameter | title-/name-holding parameter(s) |
|---|---|
|author-link= |
|author=, |last=, |last= + |first=
|
|contributor-link= |
|contributor=, |contributor-last=, |contributor-last= + |contributor-first=
|
|editor-link= |
|editor=, |editor-last=, |editor-last= + |editor-first=
|
|episode-link= |
|episode=
|
|interviewer-link= |
|interviewer=, |interviewer-last=, |interviewer-last= + |interviewer-first=
|
|series-link= |
|series=
|
|subject-link= |
|subject=
|
|title-link= |
|title=
|
|translator-link= |
|translator=, |translator-last=, |translator-last= + |translator-first=
|
Parameters checked for this error may also have the enumerated forms: |author-linkn= or |authorn-link= etc.
| |
This error occurs when any of these |<param>-link= parameters contain a wikilink or a URL, or they contain any of the characters not permitted in Wikipedia article titles per WP:TITLESPECIALCHARACTERS (except _ (underscore), used as a replacement for spaces, and #, used as a fragment identifier when linking to article sections). The prohibited characters are: < > [ ] | { }.
The |<param>-link= parameter value should contain only the title of a Wikipedia article or a link to a section of a Wikipedia article. Module:Citation/CS1 checks the |<param>-link= parameter values for wikimarkup and for a URI scheme (http://, https://, the protocol relative scheme //, etc.). Interlanguage links in any of the |<param>-link= parameters require a leading colon:
:fr:Période d'exil de Caravage
While primarily intended to catch the errors mentioned above, Module:Citation/CS1 will also catch malformed interlanguage wikilinks wherever they occur. Interlanguage wikilinks that have the form:
[[fr:Période d'exil de Caravage]]
do not create visible clickable links in the article text. Instead, these links appear in the left pane in the languages list. Module:Citation/CS1 disables interlanguage links in this form and emits an error message. The correct form is:
[[:fr:Période d'exil de Caravage]]
This error can also be caused when:
- there is a
|<param>-link=value and the matching|<param>=parameter contains a wikilink. |first=and|<param>-first=(and enumerated forms) contain a wikilink
To resolve this error, do one of the following:
- Ensure that the
|<param>-link=value is the full name of a Wikipedia article (without brackets) or a section of an article, and not a link to an external web site. - Make sure that there are no wikilinks in the matching
|<param>=parameters. - If you want to link to a URL outside of Wikipedia, move the link to
|url=or a similar parameter, if one is available in the template you are using.
Pages with this error are automatically placed in Category:CS1 errors: parameter link (7 pages).[a]
Check |pmc= value
Check |pmc= value
The |pmc= parameter is for the PubMed Central identifier. PMCs are sequential numbers beginning at 1 and counting up. Module:Citation/CS1 checks the PMC identifier to make sure that the value is a number greater than zero and less than 9100000 and that the identifier contains only digits. Further validation is not performed.
To resolve this error, ensure that the |pmc= value is correct, and that there are no letters, punctuation, or other characters. Do not include “PMC” in the value.
If the value is correct and larger than the currently configured limit of 9100000, please report this at Help talk:Citation Style 1, so that the limit can be updated.
Pages with this error are automatically placed in Category:CS1 errors: PMC (0 pages).[a]
Check |pmid= value
Check |pmid= value
The |pmid= parameter is for the PubMed identifier. PMIDs are checked to ensure that the identifier is a simple number without punctuation or spaces with a value between 1 and 35900000. Further validation is not performed.
To resolve this error, ensure that the |pmid= value is correct. If you find something that looks like a PMID and begins with “PMC”, use |pmc= instead of |pmid=.
If the value is correct and larger than the currently configured limit of 35900000, please report this at Help talk:Citation Style 1, so that the limit can be updated.
Pages with this error are automatically placed in Category:CS1 errors: PMID (0 pages).[a]
Check |rfc= value
Check |rfc= value
The |rfc= parameter is for the Internet Engineering Task Force (IETF) RFC identifier (unrelated to Wikipedia’s internal RfCs). IETF RFCs are checked to ensure that the identifier is a simple number without punctuation or spaces with a value between 1 and 9300. Further validation is not performed.
To resolve this error, ensure that the |rfc= value is correct.
If the value is correct and larger than the currently configured limit of 9300, please report this at Help talk:Citation Style 1, so that the limit can be updated.
Pages with this error are automatically placed in Category:CS1 errors: RFC (0 pages).[a]
Check |sbn= value
Check |sbn= value: <type>
Citation Style 1 and Citation Style 2 templates that contain |sbn= are checked to ensure that the SBN is the proper length (nine digits), that the SBN uses the correct optional separators (simple space or hyphen), and that the final check digit is correct according to the SBN specification. Only one SBN is allowed in this field because the whole |sbn= value is included in the citation’s COinS metadata. See also Wikipedia:COinS. More than one SBN, or characters that are not part of the SBN, corrupt the COinS metadata and may also corrupt the link to Special:BookSources.
The error message <type> indicator can be:
- length – SBN is not 9 digits
- checksum – SBN has one or more incorrect digits; look for typos and transposition
- invalid character – SBN has one or more ‘digits’ that is not in the allowed set
- invalid form – mis-positioned ‘X’ check digit
To resolve this error, ensure that the |sbn= value is correct, that only one SBN is used, that the proper optional separators are used, and that no other text is included. If the check digit is a lowercase ‘x’, change it to an uppercase ‘X’.
- Do not try to resolve the error by simply recalculating the check digit. The check digit is there to check whether the main part of the number is correct. If the SBN is failing to validate, it is likely that there is a typo in the main part of the number. In this case, recalculating the check digit results in an apparently valid ISBN that leads to the wrong source (or to nowhere).
- If the SBN as printed in your source is refusing to validate, do check both the front matter and the book cover for SBNs. It is not uncommon for the SBN to be misprinted in the front matter but correct on the cover.
- Do preview your edit and check that the new SBN does now link to the correct source.
In very rare cases, publishers have released books with malformed SBNs. If you are certain that a non-conforming SBN truly corresponds to the published work, then you can add accept-this-as-written markup around the identifier to suppress the error message. In many cases, books may have been reissued with a corrected SBN. Use a corrected SBN when possible.
Pages with this error are automatically placed in Category:CS1 errors: SBN (0 pages).[a]
Check |ssrn= value
Check |ssrn= value
The |ssrn= parameter is for the Social Science Research Network identifier. SSRNs are checked to ensure that the identifier is a simple number without punctuation or spaces with a value between 100 and 4100000. Further validation is not performed.
To resolve this error, ensure that the |ssrn= value is correct.
If the value is correct and larger than the currently configured limit of 4100000, please report this at Help talk:Citation Style 1, so that the limit can be updated.
Pages with this error are automatically placed in Category:CS1 errors: SSRN (0 pages).[a]
Check |s2cid= value
Check |s2cid= value
The |s2cid= parameter is for the Semantic Scholar corpus identifier. S2CIDs are checked to ensure that the identifier is a simple number without punctuation or spaces with a value between 1 and 250000000. Further validation is not performed.
To resolve this error, ensure that the |s2cid= value is correct.
If the value is correct and larger than the currently configured limit of 250000000, please report this at Help talk:Citation Style 1, so that the limit can be updated.
Pages with this error are automatically placed in Category:CS1 errors: S2CID (0 pages).[a]
Check |url= value
Check |url= value
External links in Citation Style 1 and Citation Style 2 templates are made from two parts: the title (|title=, |chapter=, etc.) and the URL (|url=, |archive-url=, |chapter-url=, |lay-url=, etc.). The |url= parameter and other URL parameters must begin with a supported URI scheme. The URI schemes http://, https:// and the protocol relative scheme // are most commonly used; irc://, ircs://, ftp://, news:, mailto: and gopher:// are also supported.
The URL field is checked to ensure that it contains only Latin characters and does not contain spaces. The URL may be protocol relative (begins with //). If there are no spaces and the URL is not protocol relative, then the scheme must comply with RFC 3986.[7]
Top- and second-level domain names are checked for proper form. Generally, top-level domain names must be two or more letters; second-level domain names must be two or more letters, digits, or hyphens (first and last character must be a letter or digit). Single-letter second-level domains are supported for:
- all cc TLDs (the country code is not validated)
- the .org TLD
- certain letters of the .com TLD (q, x, z)
- certain letters of the .net TLD (i, q)
Third- and subsequent-level domain names are not checked. The path portion of the URL is not checked.
Check |archive-url= value
The cs1|2 templates expect that |archive-url= will hold a unique URL for an archived snapshot of the source identified by |url= or |chapter-url= (or any of its aliases). This error message is emitted when the value assigned to |archive-url= is the same as the matching title or chapter URL.
To resolve this error, ensure that |url= and other URL parameters contain valid URLs. Online tools are available to internationalize URLs that are written in non-Latin scripts:
- “IDN Conversion Tool”. Verisign.
Pages with this error are automatically placed in Category:CS1 errors: URL (6,940 pages).[a]
Check |zbl= value
Check |zbl= value
When Citation Style 1 and Citation Style 2 templates contain |zbl=, a test is done to see if the Zbl identifier value looks like a properly defined value. The |zbl= identifier is checked to make sure that it has the form: nnnn.nnnnn where n is any digit 0–9. Up to three leading zeros in the first quartet may be omitted. Further validation of the Zbl identifier is not performed.
To resolve this error, ensure that the |zbl= value is correct.
Pages with this error are automatically placed in Category:CS1 errors: Zbl (0 pages).[a]