The ULC specification.

Schema, taxonomy, authoring patterns, conformance, and PIM mapping guides for the ULC standard.

To propose a change, file a schema change proposal in the spec repository. To fix a typo, open an issue or pull request against the source on GitHub at github.com/ulcspec/ULC.

Reference

Authoring patterns

Four real-world manufacturer publishing shapes (A: per-SKU · B: per-photometric-scenario · C: per-IES with provenance · D: per-foot linear).
Reference

Schema reference

JSON Schema Draft 2020-12. Every field documented with type, required/optional, allowed values, and example. Served at /schema/ulc.json.
Reference

Taxonomy

Closed enums for luminaire categories, mounting types, optical accessories, attestations, dimming protocols, source-file types, provenance sources.
Reference

Conformance

How the three grades (Core, Standard, Full) above an Incomplete floor are computed, why the cut points mirror a Division 26 specification, and why a fixture is graded only on what its form requires.
PIM mapping

PIM mapping guides

How to add a ULC export path alongside your existing exports for Salsify, Akeneo, SAP, and custom / in-house PIMs.
Crosswalks

Crosswalks

Field-by-field mapping from ULC to GLDF, ETIM, IES LM-63, and EULUMDAT. All four planned at v1; status flagged on the index.

Stewarded by Foad Shafighi MIES, IALD, CLD.

Specification on GitHub: github.com/ulcspec/ULC ↗ Site source: github.com/ulcspec/ulcspec.org ↗