diff --git a/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/CodeEntity.java b/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/CodeEntity.java
index cb1297cc..4721704b 100644
--- a/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/CodeEntity.java
+++ b/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/CodeEntity.java
@@ -51,6 +51,8 @@
 package eu.mihosoft.vrl.lang.model;
 
 import eu.mihosoft.vrl.workflow.VNode;
+import java.util.Map;
+import javafx.collections.ObservableMap;
 
 /**
  *
@@ -60,6 +62,8 @@ public interface CodeEntity extends ObservableCode, EventSender<CodeEvent>{
     public void setId(String id);
     public String getId();
     
+    public ObservableMap<String,Object> getMetaData();
+    
 //    public void setCode(String code);
 //    public String getCode();
     
diff --git a/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/CommentImpl.java b/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/CommentImpl.java
index ee417c76..97adef46 100644
--- a/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/CommentImpl.java
+++ b/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/CommentImpl.java
@@ -54,6 +54,8 @@
 import eu.mihosoft.vrl.lang.model.ICodeRange;
 import eu.mihosoft.vrl.lang.model.Scope;
 import eu.mihosoft.vrl.workflow.VNode;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableMap;
 
 /**
  *
@@ -69,6 +71,7 @@ public class CommentImpl implements Comment {
     private VNode node;
     private ObservableCodeImpl observableCode;
     private boolean textRenderingEnabled = true;
+    private final ObservableMap<String,Object> metadata = FXCollections.observableHashMap();
 
     public CommentImpl(String id, ICodeRange codeRange, String comment) {
         this.id = id;
@@ -208,4 +211,12 @@ public boolean isTextRenderingEnabled() {
         return textRenderingEnabled;
     }
 
+    /**
+     * @return the metadata
+     */
+    @Override
+    public ObservableMap<String,Object> getMetaData() {
+        return metadata;
+    }
+
 }
diff --git a/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/IfDeclarationImpl.java b/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/IfDeclarationImpl.java
index 5fb54258..037b1326 100644
--- a/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/IfDeclarationImpl.java
+++ b/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/IfDeclarationImpl.java
@@ -27,10 +27,10 @@ public IfDeclarationImpl(String id, Scope parent, IArgument arg) {
     @Override
     public IArgument getCheck() {
 
-        return getMetaData().getCheck();
+        return getIfMetaData().getCheck();
     }
 
-    private IfDeclarationMetaData getMetaData() {
+    private IfDeclarationMetaData getIfMetaData() {
         if (metadata == null) {
             metadata = (IfDeclarationMetaData) getScopeArgs()[0];
         }
@@ -45,9 +45,9 @@ public void defineParameters(Invocation i) {
         i.getArguments().addListener((ListChangeListener.Change<? extends IArgument> c) -> {
             while (c.next()) {
                 if (i.getArguments().isEmpty()) {
-                    getMetaData().setCheck(Argument.NULL);
+                    getIfMetaData().setCheck(Argument.NULL);
                 } else {
-                    getMetaData().setCheck(i.getArguments().get(0));
+                    getIfMetaData().setCheck(i.getArguments().get(0));
                 }
             }
         });
diff --git a/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/InvocationImpl.java b/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/InvocationImpl.java
index 0c144f90..ca4d837a 100644
--- a/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/InvocationImpl.java
+++ b/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/InvocationImpl.java
@@ -55,11 +55,11 @@
 import eu.mihosoft.vrl.workflow.WorkflowUtil;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Objects;
 import javafx.collections.FXCollections;
 import javafx.collections.ObservableList;
+import javafx.collections.ObservableMap;
 
 /**
  *
@@ -82,6 +82,8 @@ class InvocationImpl implements Invocation {
     private VNode node;
     private ObservableCodeImpl observableCode;
     private boolean textRenderingEnabled = true;
+    
+    private final ObservableMap<String,Object> metadata = FXCollections.observableHashMap();
 
     public InvocationImpl(
             Scope parent,
@@ -433,4 +435,12 @@ void setParent(Scope parent) {
         }
     }
 
+    /**
+     * @return the metadata
+     */
+    @Override
+    public ObservableMap<String,Object> getMetaData() {
+        return metadata;
+    }
+
 }
diff --git a/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/ScopeImpl.java b/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/ScopeImpl.java
index 2f4e0a3c..25a9febc 100644
--- a/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/ScopeImpl.java
+++ b/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/ScopeImpl.java
@@ -64,6 +64,7 @@
 import javafx.collections.FXCollections;
 import javafx.collections.ListChangeListener;
 import javafx.collections.ObservableList;
+import javafx.collections.ObservableMap;
 
 /**
  *
@@ -88,6 +89,8 @@ class ScopeImpl implements Scope {
     private VFlow flow;
     private ObservableCodeImpl observableCode;
     private boolean textRenderingEnabled = true;
+    
+    private final ObservableMap<String,Object> metadata = FXCollections.observableHashMap();
 
     public ScopeImpl(String id, Scope parent, ScopeType type, String name, VFlow flowParent, Object... scopeArgs) {
         this.id = id;
@@ -585,4 +588,12 @@ public boolean isTextRenderingEnabled() {
         return textRenderingEnabled;
     }
 
+    /**
+     * @return the metadata
+     */
+    @Override
+    public ObservableMap<String,Object> getMetaData() {
+        return metadata;
+    }
+
 }
diff --git a/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/WhileDeclaration_Impl.java b/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/WhileDeclaration_Impl.java
index d824ebe1..164e2cd6 100644
--- a/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/WhileDeclaration_Impl.java
+++ b/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/WhileDeclaration_Impl.java
@@ -67,10 +67,10 @@ public WhileDeclaration_Impl(String id, Scope parent, IArgument argument) {
     @Override
     public IArgument getCheck() {
 
-        return getMetaData().getCheck();
+        return getWhileMetaData().getCheck();
     }
     
-    private WhileDeclarationMetaData getMetaData() {
+    private WhileDeclarationMetaData getWhileMetaData() {
           if (metadata == null) {
             metadata = (WhileDeclarationMetaData) getScopeArgs()[0];
         }
@@ -85,9 +85,9 @@ public void defineParameters(Invocation i) {
         i.getArguments().addListener((ListChangeListener.Change<? extends IArgument> c) -> {
             while (c.next()) {
                 if (i.getArguments().isEmpty()) {
-                    getMetaData().setCheck(Argument.NULL);
+                    getWhileMetaData().setCheck(Argument.NULL);
                 } else {
-                    getMetaData().setCheck(i.getArguments().get(0));
+                    getWhileMetaData().setCheck(i.getArguments().get(0));
                 }
             }
         });
diff --git a/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/transform/CodeTransform.java b/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/transform/CodeTransform.java
index 9c2f3971..34fb8aa3 100644
--- a/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/transform/CodeTransform.java
+++ b/VRL/VRL-Lang/src/main/java/eu/mihosoft/vrl/lang/model/transform/CodeTransform.java
@@ -16,8 +16,8 @@
 public interface CodeTransform<T extends CodeEntity> {
     /**
      * 
-     * @param ce
-     * @return 
+     * @param ce conde entity to transform
+     * @return transformed copy of the cpecified code entity
      */
     public T transform(T ce);
 }