Data Models

A data model standard is a published, stewarded definition of what information exists and how it is shaped — entities, attributes, relationships, and the controlled values that fill them. It is a different question from the one the API standards catalog answers. HTTP and OpenAPI describe how you move data; FHIR, ISO 20022, CIM and NIEM describe what the data is.

These are catalogued along three axes — the layer (is it an implementation-neutral information model, a message schema, a code system, an ontology?), the domain it serves, and the origin of the body that stewards it. Every entry has been fetched and confirmed against its steward's own site; a page that could not be confirmed is not published here.

Origin is two claims, not one. A body's reach — international, regional or national — is what the column leads with; the country underneath is where that organization keeps its office. ISO is headquartered in Switzerland and ISO 20022 is not a Swiss standard, so an international body never files under a flag here. Where we have not established a steward's reach the column shows a headquarters and says so, and where we have located nothing it shows a dash rather than a guess.