diff --git a/ontology/uco-gufo.ttl b/ontology/uco-gufo.ttl
index 6f197c8..bafb5ef 100644
--- a/ontology/uco-gufo.ttl
+++ b/ontology/uco-gufo.ttl
@@ -24,7 +24,7 @@ drafting:Endurant
 	a owl:Class ;
 	rdfs:subClassOf
 		gufo:Endurant ,
-		uco-core:UcoObject
+		uco-core:UcoThing
 		;
 	rdfs:seeAlso <https://github.com/ucoProject/UCO/issues/544> ;
 	.
@@ -38,6 +38,16 @@ drafting:Perdurant
 	rdfs:seeAlso <https://github.com/ucoProject/UCO/issues/544> ;
 	.
 
+drafting:Quality
+	a owl:Class ;
+	rdfs:subClassOf
+		drafting:Endurant ,
+		gufo:Quality ,
+		uco-core:UcoInherentCharacterizationThing
+		;
+	rdfs:seeAlso <https://github.com/ucoProject/UCO/issues/535> ;
+	.
+
 uco-action:Action
 	rdfs:subClassOf drafting:Perdurant ;
 	.
@@ -46,6 +56,13 @@ uco-core:Event
 	rdfs:subClassOf drafting:Perdurant ;
 	.
 
+uco-core:Item
+	rdfs:subClassOf
+		drafting:Endurant ,
+		gufo:Object
+		;
+	.
+
 uco-identity:Organization
 	rdfs:subClassOf
 		drafting:Endurant ,
diff --git a/tests/exemplars.ttl b/tests/exemplars.ttl
index a6f52df..a95033e 100644
--- a/tests/exemplars.ttl
+++ b/tests/exemplars.ttl
@@ -1,6 +1,7 @@
 # imports: http://example.org/ontology/uco-gufo
 
 @prefix drafting: <http://example.org/ontology/drafting/> .
+@prefix gufo: <http://purl.org/nemo/gufo#> .
 @prefix kb: <http://example.org/kb/> .
 @prefix owl: <http://www.w3.org/2002/07/owl#> .
 @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@@ -8,6 +9,7 @@
 @prefix uco-action: <https://ontology.unifiedcyberontology.org/uco/action/> .
 @prefix uco-core: <https://ontology.unifiedcyberontology.org/uco/core/> .
 @prefix uco-identity: <https://ontology.unifiedcyberontology.org/uco/identity/> .
+@prefix uco-observable: <https://ontology.unifiedcyberontology.org/uco/observable/> .
 @prefix uco-types: <https://ontology.unifiedcyberontology.org/uco/types/> .
 @prefix uco-vocabulary: <https://ontology.unifiedcyberontology.org/uco/vocabulary/> .
 @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@@ -22,12 +24,25 @@ kb:Action-13c91d40-9ca0-4558-81a1-4f7db888c371
 	a uco-action:Action ;
 	.
 
+kb:ContentData-179c7e84-f72d-47f7-b6f3-3f4a1f0938bd
+	a uco-observable:ContentData ;
+	.
+
+kb:Quality-4b765c1f-362c-4562-a50f-7bb781fe4737
+	a drafting:Quality ;
+	gufo:hasReifiedQualityValue kb:Hash-4c3d0623-d365-4c69-a1a1-01523c6502fa ;
+	gufo:inheresIn kb:ContentData-179c7e84-f72d-47f7-b6f3-3f4a1f0938bd ;
+	.
+
 kb:Event-03a1a1db-0579-4427-9a51-448c32281146
 	a uco-core:Event ;
 	.
 
 kb:Hash-4c3d0623-d365-4c69-a1a1-01523c6502fa
-	a uco-types:Hash ;
+	a
+		gufo:QualityValue ,
+		uco-types:Hash
+		;
 	uco-types:hashMethod "SHA1"^^uco-vocabulary:HashNameVocab ;
 	uco-types:hashValue "da39a3ee5e6b4b0d3255bfef95601890afd80709"^^xsd:hexBinary ;
 	.