diff --git a/diagrams/core.puml b/diagrams/core.puml
index a9421ce..6f556a6 100644
--- a/diagrams/core.puml
+++ b/diagrams/core.puml
@@ -286,6 +286,12 @@
 
     "Resource_Identifier" <|-- "DOI_Identifier"
 
+    class "Wikidata_Resource_Identifier" #ffffff {
+        wikidataId : Wikidata_ID
+    }
+
+    "Resource_Identifier" <|-- "Wikidata_Resource_Identifier"
+
 !endsub
 
 !startsub Contribution_to_Project
diff --git a/entities/Wikidata_Resource_Identifier.md b/entities/Wikidata_Resource_Identifier.md
new file mode 100644
index 0000000..fc3a776
--- /dev/null
+++ b/entities/Wikidata_Resource_Identifier.md
@@ -0,0 +1,19 @@
+# Wikidata Resource Identifier
+
+## Definition
+A Wikidata<sup>[1](#fn1)</sup> identifier assigned to a [Resource](../entities/Resource.md).
+
+## Specialization of
+[Resource Identifier](../entities/Resource_Identifier.md)
+
+## Attributes
+Besides those of [Resource Identifier](../entities/Resource_Identifier.md):
+
+Wikidata ID : [Wikidata ID Type](../datatypes/Wikidata_ID.md)
+
+## Relationships
+None besides those of [Resource Identifier](../entities/Resource_Identifier.md).
+
+---
+## References
+<a name="fn1">\[1\]</a> Wikidata:Identifiers, https://www.wikidata.org/wiki/Wikidata:Identifiers