@prefix OBOE: <http://ecoinformatics.org/oboe/oboe.1.2/oboe-standards.owl#> .
@prefix OM: <http://www.ontology-of-units-of-measure.org/resource/om-2/> .
@prefix QUDT: <http://qudt.org/vocab/unit/> .
@prefix UO: <http://purl.obolibrary.org/obo/UO_> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix unit: <https://w3id.org/uom/> .

unit:SI_code a owl:AnnotationProperty ;
    rdfs:label "SI code" .

unit:UCUM_code a owl:AnnotationProperty ;
    rdfs:label "UCUM code" .

unit:mm2 a owl:NamedIndividual ;
    rdfs:label "square millimetre"@en ;
    skos:altLabel "square millimeter"@en ;
    skos:definition "A unit which is equal to 10⁻³ square metre."@en ;
    skos:exactMatch OBOE:MillimeterSquared,
        UO:0000082,
        QUDT:MilliM2,
        OM:squareMillimetre ;
    unit:SI_code "mm2" ;
    unit:UCUM_code "mm2" .