diff --git a/li.strolch.model/src/main/java/li/strolch/model/activity/Action.java b/li.strolch.model/src/main/java/li/strolch/model/activity/Action.java
index 36a0b02d2..828af5ff0 100644
--- a/li.strolch.model/src/main/java/li/strolch/model/activity/Action.java
+++ b/li.strolch.model/src/main/java/li/strolch/model/activity/Action.java
@@ -61,10 +61,20 @@ public class Action extends GroupedParameterizedElement implements IActivityElem
 	}
 
 	public Action(String id, String name, String type) {
-		super(id, name, type);
+		super(trimOrEmpty(id).intern(), trimOrEmpty(name).intern(), trimOrEmpty(type));
 		this.state = State.CREATED;
 	}
 
+	@Override
+	public void setId(String id) {
+		super.setId(trimOrEmpty(id).intern());
+	}
+
+	@Override
+	public void setName(String name) {
+		super.setName(trimOrEmpty(name).intern());
+	}
+
 	public Action(String id, String name, String type, String resourceId, String resourceType) {
 		super(id, name, type);
 		this.resourceId = resourceId;
@@ -133,7 +143,7 @@ public class Action extends GroupedParameterizedElement implements IActivityElem
 	 */
 	public void setResourceType(String resourceType) {
 		assertNotReadonly();
-		this.resourceType = resourceType;
+		this.resourceType = trimOrEmpty(resourceType).intern();
 	}
 
 	/**
diff --git a/li.strolch.model/src/main/java/li/strolch/model/parameter/AbstractParameter.java b/li.strolch.model/src/main/java/li/strolch/model/parameter/AbstractParameter.java
index 071aa6b46..77bf34002 100644
--- a/li.strolch.model/src/main/java/li/strolch/model/parameter/AbstractParameter.java
+++ b/li.strolch.model/src/main/java/li/strolch/model/parameter/AbstractParameter.java
@@ -62,6 +62,16 @@ public abstract class AbstractParameter<T> extends AbstractStrolchElement implem
 		super(trimOrEmpty(id).intern(), trimOrEmpty(name).intern());
 	}
 
+	@Override
+	public void setId(String id) {
+		super.setId(trimOrEmpty(id).intern());
+	}
+
+	@Override
+	public void setName(String name) {
+		super.setName(trimOrEmpty(name).intern());
+	}
+
 	@Override
 	public boolean isHidden() {
 		return this.hidden;
diff --git a/li.strolch.model/src/main/java/li/strolch/model/policy/PolicyDef.java b/li.strolch.model/src/main/java/li/strolch/model/policy/PolicyDef.java
index d89083703..55d483a32 100644
--- a/li.strolch.model/src/main/java/li/strolch/model/policy/PolicyDef.java
+++ b/li.strolch.model/src/main/java/li/strolch/model/policy/PolicyDef.java
@@ -39,8 +39,8 @@ public abstract class PolicyDef {
 
 	private static final Logger logger = LoggerFactory.getLogger(PolicyDef.class);
 
-	protected String type;
-	protected String value;
+	protected final String type;
+	protected final String value;
 
 	/**
 	 * Create a new policy definition
@@ -52,8 +52,8 @@ public abstract class PolicyDef {
 	 */
 	public PolicyDef(String type, String value) {
 		super();
-		this.type = type.intern();
-		this.value = value.intern();
+		this.type = type;
+		this.value = value;
 	}
 
 	/**
diff --git a/li.strolch.model/src/main/java/li/strolch/model/timedstate/AbstractStrolchTimedState.java b/li.strolch.model/src/main/java/li/strolch/model/timedstate/AbstractStrolchTimedState.java
index c2d393328..7a60ccd78 100644
--- a/li.strolch.model/src/main/java/li/strolch/model/timedstate/AbstractStrolchTimedState.java
+++ b/li.strolch.model/src/main/java/li/strolch/model/timedstate/AbstractStrolchTimedState.java
@@ -49,10 +49,20 @@ public abstract class AbstractStrolchTimedState<T extends IValue> extends Abstra
 	}
 
 	public AbstractStrolchTimedState(String id, String name) {
-		super(trimOrEmpty(id).intern(), trimOrEmpty(name).intern());
+		super(id, name);
 		this.state = new TimedState<>();
 	}
 
+	@Override
+	public void setId(String id) {
+		super.setId(trimOrEmpty(id).intern());
+	}
+
+	@Override
+	public void setName(String name) {
+		super.setName(trimOrEmpty(name).intern());
+	}
+
 	@Override
 	public boolean isHidden() {
 		return this.hidden;
@@ -75,7 +85,7 @@ public abstract class AbstractStrolchTimedState<T extends IValue> extends Abstra
 		if (StringHelper.isEmpty(interpretation)) {
 			this.interpretation = INTERPRETATION_NONE;
 		} else {
-			this.interpretation = interpretation.intern();
+			this.interpretation = interpretation;
 		}
 	}
 
@@ -90,7 +100,7 @@ public abstract class AbstractStrolchTimedState<T extends IValue> extends Abstra
 		if (StringHelper.isEmpty(uom)) {
 			this.uom = UOM_NONE;
 		} else {
-			this.uom = uom.intern();
+			this.uom = uom;
 		}
 	}