Template:Citation Style documentation/id2

The following identifiers create links and are designed to accept a single value. Using multiple values or other text will break the link and/or invalidate the identifier. In general, the parameters should include only the variable part of the identifier, e.g. |rfc=822 or |pmc=345678.

• arxiv: An arXiv document identifier, for example: |arxiv=hep-th/9205027 (pre-April 2007) or |arxiv=0706.0001 (April 2007 – December 2014) or |arxiv=1501.00001 (since January 2015). Do not include extraneous file extensions like ".pdf" or ".html". Aliases: eprint.
• asin: An Amazon Standard Identification Number (ASIN); if the first character is a digit, use isbn instead. Example: |asin=B00005N5PF. Aliases: ASIN.
  • asin-tld: The top-level domain for Amazon sites used to resolve the asin value (other than the US); valid values are: ae (United Arab Emirates), au (Australia), br (Brazil), ca (Canada), cn (People's Republic of China), de (Germany), es (Spain), fr (France), in (India), it (Italy), jp (Japan), mx (Mexico), nl (the Netherlands), pl (Poland), sa (Saudi Arabia), se (Sweden), sg (Singapore), tr (Turkey), uk (United Kingdom). Aliases: none.
• bibcode: A Bibcode reference identifier, used by a number of astronomical data systems. Example: |bibcode=1974AJ.....79..819H. Aliases: none.
• biorxiv: A bioRxiv ("Bio Archive") ID, as in the entire DOI. Example: |biorxiv=10.1101/078733 for https://biorxiv.org/content/early/2016/10/01/078733 or |biorxiv=10.1101/2020.07.24.220400 for https://doi.org/10.1101/2020.07.24.220400. Aliases: none.
• citeseerx: A CiteSeerX ID, the string of digits and dots found in a CiteSeerX URL. Example: |citeseerx=10.1.1.176.341 for https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.176.341. Aliases: none.
• doi: A digital object identifier (DOI). Example: |doi=10.1038/news070508-7. It must begins with 10. to successfully pass validation. Aliases: DOI.
  • Supports accept-this-as-written markup to bypass the validation process for DOIs using a non-standard format.
  • doi-broken-date: The date a valid DOI was found to be non-working or inactive at https://doi.org/; use the same format as other dates in the article. Aliases: none.
• eissn: An International Standard Serial Number for the electronic media (eISSN) of a serial publication, consisting of eight characters that may be split into two groups of four using a hyphen, but not an en dash or a space. Example: |eissn=1557-2986. Aliases: EISSN.
  • Supports accept-this-as-written markup to bypass the validation process for eISSNs using a non-standard format.
• hdl: A Handle System identifier for digital objects and other resources on the Internet. Example: |hdl=20.1000/100. Aliases: HDL.
• isbn: An International Standard Book Number (ISBN); use the code actually printed on or in the book, giving preference to the newer 13-digit format beginning with 978/979 when it is available, though the older 10-digit format still generates valid links if that is the only one present. Do not convert a 10-digit code to the 13-digit format just by adding the 978 prefix; the terminal digit is a calculated checksum and making changes to the numbers will make the code invalid. Hyphens in the ISBN are optional, but preferred. ISBNs can be found on the page with the publisher's information—usually the back of the title page—or beneath the barcode as a number beginning with 978 or 979 (barcodes beginning with any other numbers are not ISBNs). (See WP:ISBN and ISBN § Overview.) For sources with the even older 9-digit Standard Book Number (SBN) codes, use sbn. This parameter should hold only the ISBN, without any additional information; it is checked for length and invalid characters: anything other than numbers, spaces and hyphens, with "X" permitted as the last character for the 10-digit format or the proper check digit. Example: |isbn=978-0-8126-9593-9. Aliases: ISBN.
  • Use the {{Format ISBN}} template within the parameter – in the form |isbn={{Format ISBN|9780812695939}} – if you are unsure of how any particular value should be hyphenated, as the pattern varies by country and publisher.
  • Supports accept-this-as-written markup to bypass the validation process for ISBNs using a non-standard format.
• ismn: An International Standard Music Number (ISMN); use the ISMN actually printed on or in the work, hyphens or spaces are optional. This parameter should hold only the ISMN code without any additional information; it is checked for length and invalid characters: anything other than numbers, spaces and hyphens, and the proper check digit. Example: |ismn=979-0-9016791-7-7. Aliases: ISMN.
• issn: An International Standard Serial Number (ISSN), consisting of eight characters which may be split into two groups of four using a hyphen, but not an en dash or a space. Example: |issn=2049-3630. Aliases: ISSN.
  • Supports accept-this-as-written markup to bypass the validation process for ISSNs using a non-standard format.
• jfm: A Jahrbuch über die Fortschritte der Mathematik identifier (German for 'Yearbook on the Progress of Mathematics'); do not include "JFM" in the value. Example: |jfm=53.0144.01. Aliases: JFM.
• jstor: A Journal Storage (JSTOR) reference number. Example: |jstor=3793107. Aliases: JSTOR.
• lccn: A Library of Congress Control Number (LCCN); when present, alphabetic prefix characters are to be lower case and without a space. Examples: |lccn=79-57364, |lccn=2004042477, |lccn=e09001178. Aliases: LCCN.
• mr: A Mathematical Reviews (MR) identifier. Example: |mr=630583. Aliases: MR.
• oclc: An OCLC Control Number (OCN) for looking up publications in the WorldCat union catalog. Example: |oclc=9355469. Aliases: OCLC.
• ol: An Open Library (OL) identifier; do not include "OL" in the value. Example: |ol=7030731M. Aliases: OL.
• osti: An Office of Scientific and Technical Information (OSTI) identifier. Example: |osti=4367507. Aliases: OSTI.
• pmc: A PubMed Central (PMC) identifier; use article number for open repository full-text of a journal article and do not include "PMC" in the value. (Also see the pmid parameter; these are two distinct identifiers.) Example: |pmc=345678. Aliases: PMC.
  • pmc-embargo-date: The date that the PubMed Central identifier specified in pmc goes live; if this date is in the future, then the pmc link is not displayed until that date. Aliases: none.
• pmid: A PubMed unique identifier. (Also see the pmc parameter; these are two distinct identifiers.) Example: |pmid=17322060. Aliases: PMID.
• rfc: An IETF Request for Comments (RFC) number. Example: |rfc=3143. Aliases: RFC.
• sbn: A Standard Book Number (SBN) code consisting of nine digits, optionally formatted using hyphens or spaces. Do not include "SBN" in the value. Example: |sbn=356-02201-3. Aliases: SBN.
  • Supports accept-this-as-written markup to bypass the validation process for SBNs using a non-standard format.
• ssrn: A Social Science Research Network (SSRN) numeric identifier. Example: |ssrn=1900856. Aliases: SSRN.
• s2cid: A Semantic Scholar corpus ID. Example: |s2cid=37220927. Aliases: S2CID.
• zbl: A zbMATH Open (formerly Zentralblatt MATH) document ID code. For zbMATH search results like JFM 35.0387.02, use |jfm=35.0387.02 instead. Example: |zbl=0472.53010. Aliases: ZBL.

In very rare cases, identifiers are published which do not follow their defined standard format, or use non-conforming checksums, which would typically cause an error message to be shown by the CS1 & CS2 template families. If you encounter such a situation, do not alter them to match a different checksum. In order to suppress the error message, some identifiers (doi, eissn, isbn, issn and sbn) support a special accept-this-as-written markup which can be applied to disable the templates' error-checking function (as |<param>=((<value>))). However, if the problem is down to a mere typographical error in a third-party source, correct the identifier value instead of overriding the error message.

For some identifiers, it is possible to specify the access status using the corresponding |<param>-access= parameter.

For {{Cite journal}}, some identifiers (specifying free resources) will automatically be linked to the title when the url and title-link parameters are not present to explicitly define a link target. This behaviour can be overridden by one of a number of special keywords for the title-link parameter to manually select a specific source (such as |title-link=pmc or |title-link=doi) for auto-linking, or to disable the feature (with |title-link=none).

It is not necessary to specify a URL to a link identical to a link also produced by an identifier. The url parameter (or title-link) can then be used for providing a direct deep link to the corresponding document, or a convenience link to a resource that would not otherwise be obviously accessible.