Template:Citation Style documentation/registration
Citations of online sources that require registration or a subscription are acceptable in as documented in MEpedia:Verifiability. As a courtesy to readers and other editors, editors can signal the access restrictions of the external links included in a citation.
Four access levels can be used:
free: the source is free to read for anyone (this applies in particular to articles in open access)
registration: a free registration is required to access the source-
limited: there are other constraints (such as a cap on daily views) to freely access this source 
subscription: the source is only accessible via a paid subscription
As there are often multiple external links with different access levels in the same citation, these values are attributed to a particular external link.
Access level of |url=[edit source]
Links inserted with |url= are expected to be free to read by default. If not, editors can use one of
|url-access=subscription|url-access=registration|url-access=limited
to indicate the relevant access restriction.
Access level of identifiers[edit source]
Links inserted by identifiers such as |doi= are not expected to offer a free full text by default. If they do, editors can use |doi-access=free (in the case of |doi=) to indicate the relevant access level. The following identifiers are supported:
|bibcode=with|bibcode-access=free|doi=with|doi-access=free|hdl=with|hdl-access=free|jstor=with|jstor-access=free|ol=with|ol-access=free|osti=with|osti-access=free
Some identifiers always link to free full texts. In this case, the access level is automatically indicated by the template. This is the case for |arxiv=, |biorxiv=, |citeseerx=, |pmc=, |rfc= and |ssrn=.
Ambiguous access parameters[edit source]
The parameter |url-access=registration or |url-access=subscription can be used to indicate the access level of a citation. However, they do not indicate which link they apply to. If the restriction applies to an identifier, these parameters should be omitted.
These parameters add a link note to the end of the citation:
- url-access: For online sources that require registration, value
|url-access=registration; superseded by subscription if both are set. - url-access: For online sources that require a subscription, set
|url-access=subscription; supersedes registration if both are set.
Invalid options for |url-access= will generate an error message, the only other allowed option is limited.
