Every entity in OpenCitations Meta (https://opencitations.net/meta) is assigned persistent internal identifier called OpenCitations Meta Identifier (OMID). The OMID has structure [[entity_type_abbreviation]]/[[supplier_prefix]][[sequential_number]]. For example, the first journal article ever processed has OMID br/0601 (the full URI is https://w3id.org/oc/meta/br/0601), where br is the abbreviation of bibliographic resource, and 060 corresponds to the supplier prefix, helpful in recognising at a glance the index it belongs to (i.e., OpenCitations Meta). Finally, 1 indicates that this is the index's first bibliographic resource ever minted.

Prefix
omid
Links
Homepage
Contact
Missing Contact
Pattern for Local Unique Identifiers

Local identifiers in OpenCitations Meta Identifier should match this regular expression:
^[a-z][a-z]/06[1-9]*0[1-9][0-9]*$

Example Local Unique Identifier
br/0601   Resolve
Pattern for CURIES

Compact URIs (CURIEs) constructed from OpenCitations Meta Identifier should match this regular expression:
^omid:[a-z][a-z]/06[1-9]*0[1-9][0-9]*$

Example CURIE
omid:br/0601
Metaregistry OpenCitations Meta Identifier

The metaregistry provides mappings between the Bioregistry and other registries. There are 1 mappings to external registries for this resource with 1 unique external prefixes.

Registry Name Registry Metaprefix External Prefix Curate
Identifiers.org Identifiers.org logo miriam omid
Providers

A provider turns a local unique identifiers from a resource into a URI. Many providers are also resolvable as URLs (i.e., they can be used in a web browser).

The local unique identifier br/0601 is used to demonstrate the providers available for OpenCitations Meta Identifier. A guide for curating additional providers can be found here.

Name Metaprefix URI
OpenCitations Meta Identifier omid https://w3id.org/oc/meta/br/0601
Bioregistry bioregistry https://bioregistry.io/omid:br/0601
Identifiers.org miriam https://identifiers.org/omid:br/0601