Re3gistry: facilitating the semantic interoperability of data

The INSPIRE (Infrastructure for Spatial Information in Europe) Directive sets out the general rules for the establishment of an Infrastructure for Spatial Information in the European Community based on the Infrastructures of the Member States. Adopted by the European Parliament and the Council on 14 March 2007 (Directive 2007/2/EC), it entered into force on 25 April 2007.

INSPIRE makes it easier to find, share and use spatial data from different countries. The information is available through an online portal where it can be found broken down into different formats and topics of interest.

To ensure that these data are compatible and interoperable in a Community and cross-border context, the Directive requires the adoption of common Implementing Rules specific to the following areas:

• Metadata
• Data sets
• Network services
• Data sharing and services
• Spatial data services
• Monitoring and reporting

The technical implementation of these standards is done through Technical Guidelines, technical documents based on international standards and norms.

Inspire and semantic interoperability

These rules are considered Commission decisions or regulations and are therefore binding in each EU country. The transposition of this Directive into Spanish law is developed through Law 14/2010 of 5 July, which refers to the infrastructures and geographic information services of Spain (LISIGE) and the IDEE portal, both of which are the result of the implementation of the INSPIRE Directive in Spain.

Semantic interoperability plays a decisive role in INSPIRE. Thanks to this, there is a common language in spatial data, as the integration of knowledge is only possible when a homogenisation or common understanding of the concepts that constitute a domain or area of knowledge is achieved. Thus, in INSPIRE, semantic interoperability is responsible for ensuring that the content of the information exchanged is understood in the same way by any system.

Therefore, in the implementation of spatial data models in INSPIRE, in GML exchange format, we can find codelists that are an important part of the INSPIRE data specifications and contribute substantially to interoperability.

In general, a codelist (or code list) contains several terms whose definitions are universally accepted and understood. Code lists promote data interoperability and constitute a shared vocabulary for a community. They can even be multilingual.

INSPIRE code lists are commonly managed and maintained in the central Federated INSPIRE Registry (ROR) which provides search capabilities, so that both end-users and client applications can easily access code list values for reference.

Registers are necessary because:

• They provide the codes defined in the Technical Guidelines, Regulations and Technical Specifications necessary to implement the Directive.
• They allow unambiguous references of the elements.
• Provides unique and persistent identifiers for resources.
• Enable consistent management and version control of different elements

The code lists used in INSPIRE are maintained at:

• The Inspire Central Federated Registry (ROR).
• The register of code lists of a member state,
• The list registry of a recognised external third party that maintains a domain-specific code list.

To add a new code list, you will need to set up your own registry or work with the administration of one of the existing registries to publish your code list. This can be quite a complicated process, but a new tool helps us in this task.

Re3gistry is a reusable open-source solution, released under EUPL, that allows companies and organisations to manage and share "reference codes" through persistent URIs, ensuring that concepts are unambiguously referenced in any domain and facilitating the management of these resources graphically throughout their lifecycle.

Funded by ELISE, ISA2 is a solution recognised by the Europeans in the Interoperability Framework as a supporting tool.

Illustration 3: Image of the Re3gister interface

Re3gistry is available for both Windows and Linux and offers an easy-to-use Web Interface for adding, editing, and managing records and reference codes. In addition, it allows the management of the complete lifecycle of reference codes (based on ISO 19135: 2005 Integrated procedures for the registration of reference codes)

The editing interface also provides a flag to allow the system to expose the reference code in the format that allows its integration with RoR, so that it can eventually be imported into the INSPIRE registry federation. For this integration, Reg3gistry makes an export in a format based on the following specifications:

• The W3C Data Catalogue (DCAT) vocabulary used to model the entity registry (dcat:Catalog).
• The W3C Simple Knowledge Organisation System (SKOS) which is used to model the entity registry (skos:ConceptScheme) and the element (skos:Concept).

Other notable features of Re3gistry

• Highly flexible and customisable data models
• Multi-language content support
• Support for version control
• RESTful API with content negotiation (including OpenAPI 3 descriptor)
• Free-text search
• Supported formats: HTML, ISO 19135 XML, JSON
• Service formats can be easily added or customised (default formats): JSON and ISO 19135 XML
• Multiple authentication options
• Externally governed elements referenced through URIs
• INSPIRE record federation format support (option to automatically create RoR format)
• Easy data export and re-indexing (SOLR)
• Guides for users, administrators, and developers
• RSS feed

Ultimately, Re3gistry provides a central access point where reference code labels and descriptions are easily accessible to both humans and machines, while fostering semantic interoperability between organisations by enabling:

• Avoid common mistakes such as misspellings, entering synonyms or filling in online forms.
• Facilitate the internationalisation of user interfaces by providing multilingual labels.
• Ensure semantic interoperability in the exchange of data between systems and applications.
• Tracking changes over time through a well-documented version control system.
• Increase the value of reference codes if they are widely reused and referenced.

More about Re3gistry: