diff --git a/datatypes/ConfIDent_ID.md b/datatypes/ConfIDent_ID.md
new file mode 100644
index 0000000..ce0d3a9
--- /dev/null
+++ b/datatypes/ConfIDent_ID.md
@@ -0,0 +1,8 @@
+# The ConfIDent datatype
+
+## Definition
+The datatype that represents the [ConfIDent Identifiers](https://www.confident-conference.org/).
+
+## Specialization of
+[DOI ID](../datatypes/DOI_ID.md)
+
diff --git a/diagrams/core.puml b/diagrams/core.puml
index 97c50a4..7d8d935 100644
--- a/diagrams/core.puml
+++ b/diagrams/core.puml
@@ -413,6 +413,20 @@
 
 !endsub
 
+!startsub Event_Identifier
+    class "Event_Identifier" #ffffff {
+    }
+
+    "Event_Identifier" "0..*" <-- "1" "Event" : has identifier <
+
+    class "ConfIDent_Identifier" #ffffff {
+        confIDentId : ConfIDent_ID
+    }
+
+    "Event_Identifier" <|-- "ConfIDent_Identifier"
+
+!endsub
+
 !startsub Contribution_Statement
     class "Contribution_Statement" #ffffff {
         statement : Multilingual_String
diff --git a/entities/ConfIDent_Identifier.md b/entities/ConfIDent_Identifier.md
new file mode 100644
index 0000000..5ebc7ad
--- /dev/null
+++ b/entities/ConfIDent_Identifier.md
@@ -0,0 +1,22 @@
+# ConfIDent Identifier
+
+## Definition
+A ConfIDent<sup>[1](#fn1)</sup> identifier assigned to an [Event](../entities/Event.md).
+
+## Specialization of
+[Event Identifier](../entities/Event_Identifier.md)
+
+## Attributes
+Besides those of [Event Identifier](../entities/Event_Identifier.md):
+
+ConfIDent ID : [ConfIDent ID Type](../datatypes/ConfIDent_ID.md)
+
+## Relationships
+None besides those of [Event Identifier](../entities/Event_Identifier.md).
+
+## Constraints
+A ConfIDent Identifier can only [be assigned](../entities/Event_Identifier.md#user-content-rel__is-assigned-to) to an [Event](../entities/Event.md).
+
+---
+## References
+<a name="fn1">\[1\]</a> ConfIDent conferences registry, https://www.confident-conference.org/
\ No newline at end of file
diff --git a/entities/Event_Identifier.md b/entities/Event_Identifier.md
new file mode 100644
index 0000000..5e90464
--- /dev/null
+++ b/entities/Event_Identifier.md
@@ -0,0 +1,10 @@
+# Event Identifier
+
+## Definition
+An identifier that is assigned to an [Event](../entities/Event.md).
+
+## Attributes
+
+## Relationships
+
+<a name="rel__is-assigned-to">is-assigned-to</a> / [has-identifier](../entities/Resource.md#user-content-rel__has-identifier) : An Event Identifier can be assigned to an [Event](../entities/Event.md).