Implementing ELI

This page provides documentation and tools for countries and organisations to support their implementation of ELI.

Documentation

Guides and specifications

• ELI, the European Legislation Identifier: Good practices and guidelines​​
  Guide for publishers of legal information with a step-by-step methodology on how to implement ELI
  [Third edition published in 2024]
• ELI implementation guide: Technical aspects​​
  Guide for developers and project managers on implementing ELI, covering ELI URI identifiers, the ELI ontology, ELI metadata publishing and ELI Pillar 4
  [Third edition published in 2024]

ELI ontology

• ELI ontology and documentation​​
• ELI ‘Pillar 4’ specification – Protocol to synchronise ELI metadata
  This specification describes the protocol that enables data users to retrieve complete sets of ELI metadata and receive daily updates.

The Pillar 4 helper tool is available in the Tools section .

ELI XML Schema

ELI/XML​​ : an encoding of ELI metadata in an XML schema (XSD)

European authority tables

The Publications Office maintains and publishes a collection of multilingual authority tables. The following tables can be used for ELI implementation.

1. Administrative territorial unit​​ : controlled vocabulary that lists concepts associated with various administrative territorial units of current and past EU Member States.
2. File type​​ : controlled vocabulary listing the different types of (digital) files.
3. Language​​ : controlled vocabulary that lists concepts associated with languages.
4. Subdivision​​ : controlled vocabulary providing the subdivisions of acts used for legal citations.

The use of common authority tables facilitates data interoperability by harmonising and standardising the codes used across different websites, platforms and systems.

Implementing schema.org

A Guide to describe Legislation in schema.org

This guide is for data publishers that wish to publish structured metadata about legislation online using the schema.org legislation extension​​ . It is targeted at people involved in the ELI initiative that already publish structured data using the ELI ontology.

Tools

• ELI Validator​​
  The ELI validator is an online service that checks published ELI metadata against rules derived from the ELI ontology and then produces a validation report. It helps ELI publishers ensure that their data is accurate and compliant.
• ELI annotation tool​​
  The ELI annotation tool enables legislation publishers to annotate and publish legal texts with metadata that complies with the ELI standard. This free, open-source solution is easy to install on a server, simple to use and highly customisable to your needs. It does not require any other software to work.
• ELI Pillar 4 helper
  The Pillar 4 helper is a tool for ELI publishers implementing the Pillar 4 specification. It is a command-line Java application that helps generate sitemaps and/or RSS feeds.

ELI extension standards

Describing draft legislation (ELI-DL)

In 2021 and 2022, ELI was updated to include a new standard called ELI-DL (European Legislation Identifier for draft legislation).

This standard helps create a structured way to share information about draft laws, making it easier to follow legislative initiatives across the EU.

ELI-DL ontology and its documentation​​

ELI-Impact (ELI-I)​​

ELI offers an extension to the core ELI ontology, known as ELI-I, that provides a formal data model to represent the impact of legislative acts.

Publishers, such as official journals, can use ELI-I to describe in detail how amendments impact the original text or the most recent consolidated version.

This includes understanding the impacts of any text modifications, the process of analysing these impacts and how these changes update the consolidated (officially combined) version of the law. It also makes it possible to capture impacts of other sources, such as court decisions.

ELI and Schema.org

ELI also aims to make legislative metadata more visible online, particularly in large search engines. To achieve this, ELI proposed an extension to the schema.org vocabulary, which search engines use to process structured data. By using this extension, search engines can understand and present information about legislation more effectively.

Legislation can be published on websites that contain legislative information and can be marked up using the appropriate schema.org​​ types and properties.

Last update: 20 November 2025