Template:Citation Style documentation/registration

Citations of online sources that require registration or a subscription are acceptable in Wikipedia as documented in Verifiability § Access to sources. As a courtesy to readers and other editors, editors should signal restrictions on access to material provided via the external links included in a citation. These levels describe requirements or constraints related to accessing and viewing the cited material; they are not intended to indicate the ability to reuse, or the copyright status, of the material, since that status is not relevant to verifying claims in articles.

Four access levels can be used:

• access indicator for named identifiers:
  • free: the source is free to read for anyone
• access indicators for url-holding parameters:
  • registration: a free registration with the provider is required to access the source, even if a limited preview, abstract or review may still be available without registration
  • limited: free access is subject to limited trial and a subscription is normally required
  • subscription: the source is only accessible via a paid subscription with the provider of the source ("paywall")

As there are often multiple external links with different access levels in the same citation, each value is attributed to a specific external link.

Access indicators for url-holding parameters

Main article: WP:CONLINK

Online sources linked by |url=, |article-url=, |chapter-url=, |contribution-url=, |entry-url=, |map-url=, and |section-url= are presumed to be free-to-read. When they are not free-to-read, editors should mark those sources with the matching access-indicator parameter so that an appropriate icon is included in the rendered citation. Because the sources linked by these URL-holding parameters are presumed to be free-to-read, they are not marked as free. If the registration/limited/subscription access to the source goes dead and is no longer available, then remove the access-indicator parameter and add |archive-url= and |archive-date= values if possible.

URL-holding and access-indicator parameters

URL	Access	Allowed keywords
|url=	|url-access=	registration limited subscription
|article-url=	|article-url-access=
|chapter-url=	|chapter-url-access=
|contribution-url=	|contribution-url-access=
|entry-url=	|entry-url-access=
|map-url=	|map-url-access=
|section-url=	|section-url-access=

For example, this cites a web page that requires registration but not subscription:

{{cite web |url=https://example.com/nifty_data.php |url-access=registration |date=2021-04-15 |title=Nifty example data}}

which renders as:

"Nifty example data". 2021-04-15.

Access indicator for named identifiers

Links inserted by named identifiers are presumed to lie behind a paywall or registration barrier – exceptions listed below. When they are free-to-read, editors should mark those sources with the matching access-indicator parameter so that an appropriate icon is included in the rendered citation. When the sources linked by these named-identifier parameters are not presumed to carry a free-to-read full text (for instance because they're just abstracting services), they may not be marked as limited, registration, or subscription.

Named-identifier and access-indicator parameters

Identifier	Access	Allowed keywords
|bibcode=	|bibcode-access=	free
|doi=	|doi-access=
|hdl=	|hdl-access=
|jstor=	|jstor-access=
|ol=	|ol-access=
|osti=	|osti-access=
|ssrn=	|ssrn-access=
|s2cid=	|s2cid-access=

Some named-identifiers are always free-to-read. For those named identifiers there are no access-indicator parameters; the access level is automatically indicated by the template. These named identifiers are:

• |arxiv=
• |biorxiv=
• |citeseerx=
• |medrxiv=
• |pmc=
• |rfc=

For embargoed pmc that will become available in the future, see pmc-embargo-date.

Tracking of free DOIs

• The template is able to recognize known free-to-read DOI registrants, based on a list in Module:Citation/CS1/Configuration. Once a free registrant is identified, the 10.xxxx/... part of the DOI associated with the registrant can be added to the list under local function build_free_doi_registrants_table(). If |doi-access=free is not set, it will place the page in Category:CS1 maint: unflagged free DOI, which is routinely cleared by User:Citation bot.
• The template is also able to recognize known free-to-read journals, assuming they have a clear 10.xxxx/yyyy.... DOI pattern. Once that pattern is identified, it can be added to Module:Citation/CS1/Configuration under local extended_registrants_t = { with the format ['XXXX'] = {'YYYY'},. If there are multiple journals with the same DOI prefix, they can be grouped together with the format ['XXXX'] = {'YYYY', 'ZZZZ', '...'},.
• If you add a free registrant/free journal to the lists in Module:Citation/CS1/Configuration, leave a note at User talk:Citation bot so the bot knows about it.