Why CORA
A coordination layer produces several kinds of work. Most of it (mirror layers, machine-readable specifications, agent skills) overlaps with what individual standards bodies are doing or are extending into themselves. Two contributions are structurally distinct from that work. Each requires a position across the full landscape that an individual body is not structured to maintain for itself or for its peers, and each remains useful as the landscape matures.
Cross-standard mapping
Standards bodies maintain mappings within their own domain. Some coordinate on bilateral mappings with adjacent standards; INREV, NCREIF, and ANREV have been doing this kind of work between their reporting standards for years. A coordination layer's contribution is the n-way correspondence across the full landscape, including OSCRE, MITS, REDI, NCREIF, INREV, and their regional peers, maintained as a single machine-readable, version-pinned record.
CORA produces and maintains this correspondence. Each mapping is drafted by CORA's standards mapping working group, reviewed by the relevant standards bodies, version-pinned, and revised when the underlying standards revise. The output is a citable artifact, a structured assertion of how a concept holds across the standards that use it, rather than an opinion in prose.
{
"@context": "https://coradata.org/v0.1/context.jsonld",
"@type": "MappingRecord",
"concept": { "@type": "Class", "term": "OperatingExpense" },
"mappings": [
{
"standard": "OSCRE Industry Data Model",
"version": "3.5.0",
"term": "PropertyOperatingExpense",
"scope": "exact"
},
{
"standard": "REDI Data Model",
"version": "2024.4",
"term": "PropertyOpEx",
"scope": "broader"
},
{
"standard": "MITS Property Reference",
"version": "5.2",
"term": "ExpenseCategory",
"scope": "narrower",
"note": "MITS expense categories are unit-allocable; CORA models expense at property level above the allocation."
},
{
"standard": "NCREIF NPI Reporting",
"version": "2025.1",
"term": "OperatingExpense",
"scope": "exact"
}
],
"provenance": {
"establishedBy": "CORA Standards Mapping working group",
"reviewedBy": ["OSCRE Data Standards Committee", "RETTC MITS working group"],
"lastReviewedAt": "2026-03-15"
}
}Illustrative. A MappingRecord asserts how a single concept (here, OperatingExpense) holds across multiple standards, with SKOS-style scope notes and provenance back to the bodies that reviewed each entry. The v0.1 specification will publish the schema in full.
Longitudinal record of standards evolution
Standards evolve. They tighten definitions, expand or narrow scope, restructure schema, and reissue. Each change introduces drift: structural drift in schema, semantic drift in definitions, coverage drift in what the standard covers. Drift is unavoidable - it is the cost of standards that respond to changing industry conditions.
What does not yet exist in the landscape is a neutral, public record of where and when this drift occurs across the full set of standards. Tracking drift within a single body's own corpus is something that body is structured to do for its own purposes. Tracking drift across the full landscape, across versions of one standard and across peer standards together, calls for a position outside any single body's perimeter. A coordination layer is structurally placed to take that position.
CORA's drift register is that record. It tracks structural, semantic, and coverage drift across versions and across standards, with provenance back to the source documents. Each entry is reviewable, citable, and revisable as the methodology matures.
{
"@context": "https://coradata.org/v0.1/context.jsonld",
"@type": "DriftRecord",
"standard": "OSCRE Industry Data Model",
"from": { "version": "3.4.0", "asOf": "2024-09-15" },
"to": { "version": "3.5.0", "asOf": "2025-02-28" },
"driftType": "semantic",
"concept": { "@type": "Class", "term": "OperatingExpense" },
"summary": "Definition narrowed to exclude capital reserves; reserves now reported separately.",
"impact": "CORA crosswalks to NCREIF NPI expense categories require updated reconciliation.",
"provenance": {
"sourceDocument": "OSCRE IDM 3.5.0 Release Notes",
"verifiedBy": "CORA Drift & Tooling working group",
"recordedAt": "2025-03-04"
}
}Illustrative. A DriftRecord captures a single instance of drift - here, a semantic narrowing in OSCRE IDM 3.5.0 - with the affected concept, the change summary, the downstream impact on existing mappings, and provenance back to the source release notes. The v0.1 specification will publish the schema and the initial register together.
These two contributions are sufficient to justify CORA's role alongside the standards bodies. They do not require CORA to compete with any standards body, replace any standard, or claim authority CORA does not have. They require only the neutral position and the sustained operational discipline to do the cross-cutting and longitudinal work that the structure of the standards landscape does not place inside any single body.