diff --git a/ontology/owl/owl.ttl b/ontology/owl/owl.ttl
index ced847dd..2f5ecc72 100644
--- a/ontology/owl/owl.ttl
+++ b/ontology/owl/owl.ttl
@@ -149,12 +149,12 @@ uco-owl:Disjointedness-C-DT-shape
 	sh:sparql [
 		a sh:SPARQLConstraint ;
 		rdfs:seeAlso <https://www.w3.org/TR/2012/REC-owl2-syntax-20121211/#Typing_Constraints_of_OWL_2_DL> ;
-		sh:message "An IRI may not be a member of both an owl:Class and owl:Datatype."@en ;
+		sh:message "An IRI may not be a member of both an owl:Class and rdfs:Datatype."@en ;
 		sh:select """
 			PREFIX owl: <http://www.w3.org/2002/07/owl#>
 			SELECT $this
 			WHERE {
-				$this a owl:Datatype ;
+				$this a rdfs:Datatype ;
 			}
 		""" ;
 	] ;
diff --git a/ontology/uco/core/core.ttl b/ontology/uco/core/core.ttl
index e061bd54..ab907fcf 100644
--- a/ontology/uco/core/core.ttl
+++ b/ontology/uco/core/core.ttl
@@ -121,7 +121,6 @@ core:ContextualCompilation
 	rdfs:comment "A contextual compilation is a grouping of things sharing some context (e.g., a set of network connections observed on a given day, all accounts associated with a given person)."@en ;
 	sh:property [
 		sh:class core:UcoObject ;
-		sh:minCount "1"^^xsd:integer ;
 		sh:nodeKind sh:IRI ;
 		sh:path core:object ;
 	] ;
diff --git a/ontology/uco/observable/observable.ttl b/ontology/uco/observable/observable.ttl
index 9583efbb..6f5553b2 100644
--- a/ontology/uco/observable/observable.ttl
+++ b/ontology/uco/observable/observable.ttl
@@ -5056,6 +5056,20 @@ observable:ObservableRelationship
 		;
 	rdfs:label "ObservableRelationship"@en ;
 	rdfs:comment "An observable relationship is a grouping of characteristics unique to an assertion of an association between two observable objects."@en ;
+	sh:property
+		[
+			sh:class observable:Observable ;
+			sh:message "The source on an ObservableRelationship is expected to be typed as an Observable, and the noted value node is not.  This will be an error in UCO 2.0.0."@en ;
+			sh:path core:source ;
+			sh:severity sh:Warning ;
+		] ,
+		[
+			sh:class observable:Observable ;
+			sh:message "The target on an ObservableRelationship is expected to be typed as an Observable, and the noted value node is not.  This will be an error in UCO 2.0.0."@en ;
+			sh:path core:target ;
+			sh:severity sh:Warning ;
+		]
+		;
 	sh:targetClass observable:ObservableRelationship ;
 	.