Documentation
Guides, references, and deep dives
Everything you need to understand IEC CDD, browse the OpenCDD Browser, and use CDD data in your own applications.
Getting Started
New here? Start with these.Getting started
A five-minute tour for first-time visitors — what OpenCDD is, where to click first, and what to expect on each page.
What is IEC CDD?
A shared, versioned, multilingual dictionary of product characteristics maintained by IEC. The standard behind OpenCDD.
What is OpenCDD?
The OpenCDD ecosystem — open-source tooling around the IEC Common Data Dictionary.
Browse the dictionary
A complete UI walkthrough — homepage, dictionary landing, entity detail pages, class tree, search, and language switcher.
Concepts
Understand the mental model.The CDD data model
IRDIs, classes, properties, value lists, units, relations, and the meta-class hierarchy that ties them together.
IRDIs in depth
How International Registration Data Identifiers are built, parsed, and cited — with worked examples from every OpenCDD dictionary.
CDD ontology vs UML and RDF
Why CDD's four-layer model and power-type semantics differ from UML class diagrams and RDF/OWL ontologies, in IEC 61360's own terminology.
Guides
Step-by-step recipes for common tasks.Using CDD data
A practical consumer guide — the JSON shape, how to load a dictionary, and when CDD is the right tool.
Query cookbook
Copy-paste recipes for loading and querying CDD data in TypeScript, Ruby, and Python — finding entities, walking hierarchies, resolving references, exporting slices.
Downloads — Parcel, JSON, CDDAL, CSV
Every format you can pull from the OpenCDD browser.
Version History, Time Travel, and Diff
Navigate every published revision of any entity in the OpenCDD browser.
Reference
Detailed specifications and lookup.CDDAL — CDD Authoring Language
A human-readable, plain-text format for authoring and exchanging IEC Common Data Dictionary data. Round-trips with the Parcel xlsx format, supports file inclusion, multilingual values, and deterministic output.
The Parcel Excel Format
How IEC 62656-1 Parcel workbooks are structured — reserved sheets, per-dictionary sheets, the 12-row header, and how to read them programmatically.
Project
Contribute to OpenCDD.Looking for something specific?
Press ⌘K to search across all dictionaries, or browse the dictionaries dashboard.