diff --git a/asn/CPM_CommonDataTypes.asn b/asn/CPM_CommonDataTypes.asn
index 5fe7781b07d5f9be8752d1eb9280ff53643e9bb9..e9cb9d720bc07fe78c68a361c81b00b699a15e29 100644
--- a/asn/CPM_CommonDataTypes.asn
+++ b/asn/CPM_CommonDataTypes.asn
@@ -252,8 +252,8 @@ MessageSegmentInfo ::= SEQUENCE {
 ObjectClassDescription ::= SEQUENCE (SIZE(1..8)) OF ObjectClassWithConfidence
 
 -- @brief Object Class with Confidence
--- Describes the classification of a detected object. The object can be classified into one of five
--- categories: unknown, vehicle, person, animal and other. The classification is provided with a
+-- Describes the classification of a detected object. The object can be classified into one of four
+-- categories: vehicle, person, animal and other. The classification is provided with a
 -- confidence indication.
 ObjectClassWithConfidence ::= SEQUENCE {
     -- @todo
@@ -263,10 +263,8 @@ ObjectClassWithConfidence ::= SEQUENCE {
 }
 
 -- @brief Object Class
--- The class that best describes the detected object. Each class provides optional subclasses and
--- an associated confidence for the subclass.
+-- The class that best describes the detected object. Each class provides optional subclasses.
 ObjectClass ::= CHOICE {
-    unknownSubclass     UnknownSubclassType,
     vehicleSubclass     VehicleSubclassType,
     personSubclass      PersonSubclassType,
     animalSubclass      AnimalSubclassType,
@@ -294,12 +292,6 @@ NodeOffsetPointZ ::= CHOICE {
     node-Z6 Offset-B16  -- node is within 327.67m of last node
 }
 
--- @brief Unknown Subclass Type
--- Describes the subclass of a detected object for class unknown.
--- @unit n/a
-UnknownSubclassType ::= INTEGER {
-    unknown             (0)
-} (0..255)
 
 -- @brief Animal Subclass Type
 -- Describes the subclass of a detected object for class animal.