diff --git a/ontology/saref4ehaw.ttl b/ontology/saref4ehaw.ttl
index 9dcdca2e740a786d9926abb4ac7ca7df53183f48..f5b01b90b31864bac152e390524dc39c16cb02da 100644
--- a/ontology/saref4ehaw.ttl
+++ b/ontology/saref4ehaw.ttl
@@ -5,6 +5,7 @@
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
+@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix vann: <http://purl.org/vocab/vann/> .
@prefix voaf: <http://purl.org/vocommons/voaf#> .
@prefix saref: <https://saref.etsi.org/core/> .
@@ -97,6 +98,10 @@ vann:preferredNamespaceUri rdf:type owl:AnnotationProperty .
# Object Properties
#################################################################
+### http://www.w3.org/2004/02/skos/core#broader
+skos:broader rdf:type owl:ObjectProperty .
+
+
### https://saref.etsi.org/core/consistsOf
saref:consistsOf rdf:type owl:ObjectProperty ;
rdfs:domain s4ehaw:Ban ;
@@ -130,14 +135,6 @@ s4ehaw:hasActivity rdf:type owl:ObjectProperty ;
rdfs:label "has activity"@en .
-### https://saref.etsi.org/saref4ehaw/hasAgeCategory
-s4ehaw:hasAgeCategory rdf:type owl:ObjectProperty ;
- rdfs:domain s4ehaw:HealthActor ;
- rdfs:range s4ehaw:AgeCategory ;
- rdfs:comment "The age group of a health actor, e.g. old or young."@en ;
- rdfs:label "has age category"@en .
-
-
### https://saref.etsi.org/saref4ehaw/hasBanApplicationDomain
s4ehaw:hasBanApplicationDomain rdf:type owl:ObjectProperty ;
rdfs:domain s4ehaw:Ban ;
@@ -915,12 +912,6 @@ s4ehaw:Activity rdf:type owl:Class ;
rdfs:label "Activity"@en .
-### https://saref.etsi.org/saref4ehaw/AgeCategory
-s4ehaw:AgeCategory rdf:type owl:Class ;
- rdfs:comment "The age group of a health actor, e.g. old or young."@en ;
- rdfs:label "Age category"@en .
-
-
### https://saref.etsi.org/saref4ehaw/AlarmCommand
s4ehaw:AlarmCommand rdf:type owl:Class ;
rdfs:subClassOf saref:Command ;
@@ -1265,6 +1256,11 @@ s4envi:FrequencyUnit rdf:type owl:Class .
# Individuals
#################################################################
+### https://saref.etsi.org/saref4ehaw/AgeCategory
+s4ehaw:AgeCategory rdf:type owl:NamedIndividual ,
+ saref:State .
+
+
### https://saref.etsi.org/saref4ehaw/AlcoholDrinking
s4ehaw:AlcoholDrinking rdf:type owl:NamedIndividual ,
s4ehaw:Habit ;
@@ -1359,7 +1355,8 @@ s4ehaw:OcularImpairment rdf:type owl:NamedIndividual ,
### https://saref.etsi.org/saref4ehaw/Old
s4ehaw:Old rdf:type owl:NamedIndividual ,
- s4ehaw:AgeCategory ;
+ saref:State ;
+ skos:broader s4ehaw:AgeCategory ;
rdfs:comment "Old, one user age category."@en ;
rdfs:label "Old"@en .
@@ -1457,7 +1454,8 @@ s4ehaw:WristLocation rdf:type owl:NamedIndividual ,
### https://saref.etsi.org/saref4ehaw/Young
s4ehaw:Young rdf:type owl:NamedIndividual ,
- s4ehaw:AgeCategory ;
+ saref:State ;
+ skos:broader s4ehaw:AgeCategory ;
rdfs:comment "Young, one user age category."@en ;
rdfs:label "Young"@en .