Glossary · Administrative metadata

iiRDS ExternalClassification

Also known as: external classification, standard classification

In iiRDS (intelligent information Request and Delivery Standard), an ExternalClassification maps a resource to a class in an external classification system that does not provide IRIs, such as ECLASS, VDI 2770 or IEC 61355. It consists of a classification identifier, exactly one classification domain and an optional version.

iiRDS term
Ontology
Information architecture

In one sentence

An iiRDS ExternalClassification maps content or products to external classification systems such as ECLASS or VDI 2770 that have no IRIs of their own.

Example

An operating manual is classified as “03-02 Operation” according to VDI 2770 and as “&PDC Instructions and manuals” according to IEC 61355.

In-depth wiki articleiiRDS ExternalClassification: mapping content to ECLASS, VDI 2770 and other systems

How it applies

Technical documentation: Product variants, product features, components, information objects and information units can be linked with iirds:has-external-classification. The value goes in iirds:classificationIdentifier, the version in iirds:classificationVersion, the system in iirds:has-classification-domain.
Product data: Classification domains may state their type with iirds:has-classification-type, for example iirds:EclassIRDI for ECLASS identifiers — which connects documentation with the product data that engineering and sales already use.
Limits: External classifications are only for systems without IRIs. A vocabulary that is already available as RDF, such as schema.org or Dublin Core, is referenced directly, and an external classification must never replace a proprietary extension.
AI and retrieval: Shared classification codes let content from different manufacturers be compared and searched together, without first agreeing on a common vocabulary.

External classification vs. information type

An information type such as iirds:OperatingInstructions is part of the iiRDS vocabulary. An external classification records the class a resource has in someone else's system. A document often has both.

In RDF

Adapted from the VDI 2770 example in the iiRDS specification. Shown in Turtle for readability — inside a package, metadata.rdf is written in RDF/XML.

@prefix iirds: <http://iirds.tekom.de/iirds#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .

<https://example.com/iirds/operating-manual> a iirds:Document ;
    iirds:has-document-type iirds:OperatingInstructions ;
    iirds:has-external-classification [
        a iirds:ExternalClassification ;
        iirds:classificationIdentifier "03-02" ;
        rdfs:label "Operation"@en ;
        iirds:has-classification-domain <https://example.com/classification-domains/vdi2770>
    ] .

<https://example.com/classification-domains/vdi2770> a iirds:ClassificationDomain .