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URI Schemes

Last updated on June 07, 2019

Cobaltmetrics stores identifiers as URIs, so every identifier consists of a scheme, a colon, and a value. We support a wide variety of URI schemes, and our URI transmutation API can be use to convert between schemes and collate all URIs known to directly or indirectly identify the same resource.

See also our statistics API for a machine-readable list of supported URI schemes.

Primary URI Schemes

Primary URI schemes are schemes for identifiers that can be found in the wild, either as standalone URIs or embedded in URI paths, query strings, or fragments.

Scheme Description
ark Archival Resource Key
arxiv arXiv Identifier
bcp Best Current Practice Number
bibcode Bibliographic Code
bic Bank Identifier Code
cik Central Index Key
coden CODEN
cve Common Vulnerabilities and Exposures
doi Digital Object Identifier
ein IRS Employer Identification Number
eudract European Clinical Trials Database Number
ftp File Transfer Protocol
fyi For Your Information Number
google-books Google Books Identifier
google-scholar Google Scholar Author Identifier
gopher Gopher
grid Global Research Identifier
hdl Handle
http Hypertext Transfer Protocol
https HTTP Secure
info Info URI
isbn International Standard Book Number
isni International Standard Name Identifier
issn International Standard Serial Number
jstor JSTOR Identifier
lccn Library of Congress Control Number
lei Legal Entity Identifier
lsid Life Science Identifier
magnet Magnet Link
mailto* Email address
mjid medIND Journal Identifier
mr Mathematical Reviews Identifier
nct National Clinical Trial Number
nda New Drug Application Number
nlmid National Library of Medicine Identifier
oai Open Archives Initiative Identifier
orcid Open Researcher and Contributor Identifier
patent Patent Number
pii Publisher Item Identifier
pmcid PubMed Central Identifier
pmid PubMed Identifier
researcherid ResearcherID
rfc Request for Comments Number
rin Ringgold Identifier
scopus Scopus Author Identifier
ssrn Social Science Research Network Identifier
std Internet Standard Number
tweet Tweet Identifier
urn Uniform Resource Name
usc United States Code
viaf Virtual International Authority File Identifier
webcite-cache WebCite Cache Identifier
webcite-hash WebCite Hash Identifier
webcite-id WebCite Identifier
wikidata Wikidata Identifier
youtube YouTube Identifier
zbl Zentralblatt MATH Identifier
zenodo Zenodo Record Identifier

*Supporting email addresses took a lot of consideration to balance obvious privacy concerns and important usability upsides. We do not want to risk redistributing email addresses via our API, even if these addresses are publicly available in our data sources. Cobaltmetrics will never output an email address unless it was explicitly entered into our search bar or sent to our API. See our blog post on privacy-preserving altmetrics for more information.

Secondary URI Schemes

Secondary URI schemes are used for secondary URIs, i.e. URIs that are automatically derived from primary URIs.

Secondary URIs are useful to execute coarse-grained search queries that aggregate e.g. all citations to any URL from a given website.

Scheme Description
host Host (hostname or IP address). host URIs are automatically extracted from ftp, http, https, and mailto URIs.
domain Domain name. domain URIs are automatically extracted from host URIs, using the effective top-level domain to determine which component of a host is the NIC-assigned domain name.