diff --git a/RELEASE_NOTES.html b/RELEASE_NOTES.html
index a0dfc3b..de2303e 100644
--- a/RELEASE_NOTES.html
+++ b/RELEASE_NOTES.html
@@ -74,7 +74,9 @@
     <li>Bug fixes</li>
   </ul>
   <p>
-    This release requires an update of script projects and its descriptors in the UIMA Ruta Workbench, e.g, by deleting all descriptors and updating the script project. Right-click on a project and select "UIMA Ruta -> Convert to UIMA Ruta project.
+    This release requires an update of script projects and its descriptors in the UIMA Ruta Workbench. 
+    There are several ways to achieve this. The recommended way is to right-click on the UIMA Ruta project and select "UIMA Ruta -> Convert to UIMA Ruta project", which will update all provided descriptors.
+    Then, select the project and press "Project -> Clean..." in the menu, which will regenerate all descriptors of your scripts based on the new templates.
   </p>
   
 </p>
diff --git a/ruta-core/src/main/java/org/apache/uima/ruta/expression/feature/LazyFeature.java b/ruta-core/src/main/java/org/apache/uima/ruta/expression/feature/LazyFeature.java
index fc1858b..00411d8 100644
--- a/ruta-core/src/main/java/org/apache/uima/ruta/expression/feature/LazyFeature.java
+++ b/ruta-core/src/main/java/org/apache/uima/ruta/expression/feature/LazyFeature.java
@@ -53,31 +53,37 @@
   
   @Override
   public int compareTo(Feature o) {
+    checkDelegate();
     return delegate.compareTo(o);
   }
 
   @Override
   public Type getDomain() {
+    checkDelegate();
     return delegate.getDomain();
   }
 
   @Override
   public Type getRange() {
+    checkDelegate();
     return delegate.getRange();
   }
 
   @Override
   public String getName() {
+    checkDelegate();
     return delegate.getName();
   }
 
   @Override
   public String getShortName() {
+    checkDelegate();
     return delegate.getShortName();
   }
 
   @Override
   public boolean isMultipleReferencesAllowed() {
+    checkDelegate();
     return delegate.isMultipleReferencesAllowed();
   }
 
@@ -85,5 +91,11 @@
     return featureName;
   }
 
+  private void checkDelegate() {
+    if(delegate == null) {
+      throw new RuntimeException("Feature with name '"+ featureName +"' has not yet been resolved. Most likely, it is not defined for the given type.");
+    }
+    
+  }
 
 }
diff --git a/ruta-core/src/test/java/org/apache/uima/ruta/expression/IndexedListExpressionTest.java b/ruta-core/src/test/java/org/apache/uima/ruta/expression/IndexedListExpressionTest.java
index d7cf655..608ef7d 100644
--- a/ruta-core/src/test/java/org/apache/uima/ruta/expression/IndexedListExpressionTest.java
+++ b/ruta-core/src/test/java/org/apache/uima/ruta/expression/IndexedListExpressionTest.java
@@ -22,31 +22,29 @@
 import org.apache.uima.cas.CAS;
 import org.apache.uima.ruta.engine.Ruta;
 import org.apache.uima.ruta.engine.RutaTestUtils;
+import org.junit.Ignore;
 import org.junit.Test;
 
 public class IndexedListExpressionTest {
+
   @Test
-  public void test() {
+  @Ignore
+  public void test() throws Exception{
     String document = "Some text.";
     String script = "";
-    script += "STRINGLIST sl = {\"Some\", \"text\"}";
+    script += "STRINGLIST sl = {\"Some\", \"text\"};";
     script += "W.ct == sl[0]{-> T1};";
     script += "W.ct == sl[1]{-> T2};";
     script += "W{REGEXP(sl[0]) -> T3};";
     script += "W{REGEXP(sl[1]) -> T4};";
 
-    CAS cas = null;
-    try {
-      cas = RutaTestUtils.getCAS(document);
-      Ruta.apply(cas, script);
-    } catch (Exception e) {
-      e.printStackTrace();
-    }
+    CAS cas = RutaTestUtils.getCAS(document);
+    Ruta.apply(cas, script);
 
-//    RutaTestUtils.assertAnnotationsEquals(cas, 1, 1, "Some");
-//    RutaTestUtils.assertAnnotationsEquals(cas, 2, 1, "text");
-//    RutaTestUtils.assertAnnotationsEquals(cas, 3, 1, "Some");
-//    RutaTestUtils.assertAnnotationsEquals(cas, 4, 1, "text");
-    
+    RutaTestUtils.assertAnnotationsEquals(cas, 1, 1, "Some");
+    RutaTestUtils.assertAnnotationsEquals(cas, 2, 1, "text");
+    RutaTestUtils.assertAnnotationsEquals(cas, 3, 1, "Some");
+    RutaTestUtils.assertAnnotationsEquals(cas, 4, 1, "text");
+
   }
 }
diff --git a/ruta-docbook/src/docbook/tools.ruta.howtos.xml b/ruta-docbook/src/docbook/tools.ruta.howtos.xml
index 2d6229e..c170ff6 100644
--- a/ruta-docbook/src/docbook/tools.ruta.howtos.xml
+++ b/ruta-docbook/src/docbook/tools.ruta.howtos.xml
@@ -263,7 +263,8 @@
  A FileSet specifying the UIMA Ruta script files that should be built. 
  
  If this parameter is not specified, then all UIMA Ruta script files 
- in the output directory (e.g., target/classes) of the project will be built. 
+ in the output directory (e.g., target/classes) of the project will 
+ be built. 
  
  default value: none
  <scriptFiles>
@@ -288,8 +289,8 @@
  <analysisEngineOutputDirectory>${project.build.directory}/
   generated-sources/ruta/descriptor</analysisEngineOutputDirectory>
 
- <!-- The template descriptor for the generated type system. By default the 
-   descriptor of the maven dependency is loaded. -->
+ <!-- The template descriptor for the generated type system. 
+  By default the descriptor of the maven dependency is loaded. -->
  <!-- default value: none -->
  <!-- not used in this example <typeSystemTemplate>...
    </typeSystemTemplate> -->
diff --git a/ruta-docbook/src/docbook/tools.ruta.language.syntax.xml b/ruta-docbook/src/docbook/tools.ruta.language.syntax.xml
index b45631e..6b8acad 100644
--- a/ruta-docbook/src/docbook/tools.ruta.language.syntax.xml
+++ b/ruta-docbook/src/docbook/tools.ruta.language.syntax.xml
@@ -83,9 +83,11 @@
                                ("," Identifier)* ("=" NumberExpression)?)
                      | ("BOOLEAN" Identifier ("," Identifier)*
                                                 ("=" BooleanExpression)?)
-                     | ("ANNOTATION" Identifier ("=" AnnotationExpression)?)
-                     | ("WORDLIST" Identifier ("=" WordListExpression | StringExpression)?)
-                     | ("WORDTABLE" Identifier ("=" WordTableExpression | StringExpression)?)
+                     | ("ANNOTATION" Identifier("="AnnotationExpression)?)
+                     | ("WORDLIST" Identifier ("=" WordListExpression 
+                                                | StringExpression)?)
+                     | ("WORDTABLE" Identifier ("=" WordTableExpression 
+                                                | StringExpression)?)
                      | ("TYPELIST" Identifier ("=" TypeListExpression)?)
                      | ("STRINGLIST" Identifier
                                              ("=" StringListExpression)?)
@@ -102,13 +104,13 @@
                       | 'SENTENCEEND' | 'W' | 'PM' | 'ANY' | 'ALL'
                       | 'SPACE' | 'BREAK')
 BlockDeclaration    -> "BLOCK" "(" Identifier ")" RuleElementWithCA
-                                                       "{" Statements "}"]]></programlisting>
-actionDeclaration   -> "ACTION" Identifier "(" ("VAR"? VarType Identifier)? 
-                      ("," "VAR"? VarType Identifier)*")"  
+                                                       "{" Statements "}"
+actionDeclaration   -> "ACTION" Identifier "(" ("VAR"? VarType 
+                       Identifier)? ("," "VAR"? VarType Identifier)*")"  
                       "=" Action ( "," Action)* ";"
-conditionDeclaration-> "CONDITION" Identifier "(" ("VAR"? VarType Identifier)? 
-                      ("," "VAR"? VarType Identifier)*")"  
-                      "=" Condition ( "," Condition)* ";"  
+conditionDeclaration-> "CONDITION" Identifier "(" ("VAR"? VarType 
+                       Identifier)? ("," "VAR"? VarType Identifier)*")"  
+                      "=" Condition ( "," Condition)* ";"]]></programlisting>
     Syntax of statements and rule elements:
     <programlisting><![CDATA[SimpleStatement        -> SimpleRule | RegExpRule | ConjunctRules 
                           | DocumentActionRule
@@ -155,7 +157,8 @@
   <para>
     It is also possible to use specific expression as implicit conditions or action additionally to the set of available conditions and actions.
         <programlisting><![CDATA[Condition -> BooleanExpression | FeatureMatchExpression
-Action    -> TypeExpression | FeatureAssignmentExpression | VariableAssignmentExpression 
+Action    -> TypeExpression | FeatureAssignmentExpression 
+              | VariableAssignmentExpression 
 ]]></programlisting>
   
 
diff --git a/ruta-docbook/src/docbook/tools.ruta.language.xml b/ruta-docbook/src/docbook/tools.ruta.language.xml
index 286ff78..63df653 100644
--- a/ruta-docbook/src/docbook/tools.ruta.language.xml
+++ b/ruta-docbook/src/docbook/tools.ruta.language.xml
@@ -850,8 +850,7 @@
       construct, and ignore all filtering settings.
     </para>
 
-    <programlisting><![CDATA[
-RegExpRule        -> StringExpression "->" GroupAssignment 
+    <programlisting><![CDATA[RegExpRule        -> StringExpression "->" GroupAssignment 
                      ("," GroupAssignment)* ";"
 GroupAssignment   -> TypeExpression FeatureAssignment?
                      | NumberEpxression "=" TypeExpression 
diff --git a/ruta-docbook/src/docbook/tools.ruta.overview.xml b/ruta-docbook/src/docbook/tools.ruta.overview.xml
index 84131d2..7507df7 100644
--- a/ruta-docbook/src/docbook/tools.ruta.overview.xml
+++ b/ruta-docbook/src/docbook/tools.ruta.overview.xml
@@ -391,7 +391,8 @@
     <programlisting><![CDATA[DECLARE Annotation EmplRelation 
    (Employee employeeRef, Employer employerRef);
 e1:Employer # EmploymentIndicator # e2:Employee)
-    {-> EmplRelation, EmplRelation.employeeRef=e2, EmplRelation.employerRef=e1};]]></programlisting>
+    {-> EmplRelation, EmplRelation.employeeRef=e2, 
+        EmplRelation.employerRef=e1};]]></programlisting>
     
     <para>
       Global variables for annotations are declared like other variables and are able to store annotations
diff --git a/ruta-ep-ide-ui/src/main/java/org/apache/uima/ruta/ide/validator/LanguageCheckerVisitor.java b/ruta-ep-ide-ui/src/main/java/org/apache/uima/ruta/ide/validator/LanguageCheckerVisitor.java
index 0e3fead..d7ee795 100644
--- a/ruta-ep-ide-ui/src/main/java/org/apache/uima/ruta/ide/validator/LanguageCheckerVisitor.java
+++ b/ruta-ep-ide-ui/src/main/java/org/apache/uima/ruta/ide/validator/LanguageCheckerVisitor.java
@@ -614,6 +614,12 @@
         return false;
       }
       RutaVariableReference ref = (RutaVariableReference) s;
+      if(ref.getType() == RutaTypeConstants.RUTA_TYPE_WT || ref.getType() == RutaTypeConstants.RUTA_TYPE_WL) {
+        if(StringUtils.isBlank(ref.getName())) {
+          // declaration with a string expression: do not check
+          return false;
+        }
+      }
       if ((ref.getType() & RutaTypeConstants.RUTA_TYPE_AT) != 0) {
         // types
         String name = ref.getName();
diff --git a/ruta-ep-ide/src/main/antlr3/org/apache/uima/ruta/ide/core/parser/RutaParser.g b/ruta-ep-ide/src/main/antlr3/org/apache/uima/ruta/ide/core/parser/RutaParser.g
index 3210be7..7f605ee 100644
--- a/ruta-ep-ide/src/main/antlr3/org/apache/uima/ruta/ide/core/parser/RutaParser.g
+++ b/ruta-ep-ide/src/main/antlr3/org/apache/uima/ruta/ide/core/parser/RutaParser.g
@@ -486,14 +486,14 @@
 		 stmts.add(StatementFactory.createDeclarationsStatement(type, decls, init));
 		 }
         |
-        type = WORDLIST id = Identifier (ASSIGN_EQUAL (wl = wordListExpression | wl = stringExpression))? SEMI
+        type = WORDLIST id = Identifier (ASSIGN_EQUAL wl = wordListOrStringExpression )? SEMI
         {
         addVariable(id.getText(), type.getText());
         decls.add(StatementFactory.createListVariable(id,type,wl));
         stmts.add(StatementFactory.createDeclarationsStatement(type, decls, wl));
         }
         |
-        type = WORDTABLE id = Identifier (ASSIGN_EQUAL (wt = wordTableExpression | wt = stringExpression))?  SEMI
+        type = WORDTABLE id = Identifier (ASSIGN_EQUAL wt = wordTableOrStringExpression)?  SEMI
         {
         addVariable(id.getText(), type.getText());
         decls.add(StatementFactory.createTableVariable(id,type,wt));
@@ -2447,6 +2447,15 @@
 	;
 
 
+wordListOrStringExpression returns [Expression expr = null]
+	:
+	(stringExpression)=>id = stringExpression
+	{expr = ExpressionFactory.createListVariableReference(id);}
+	|
+	e = wordListExpression
+	{expr = e;}
+	;
+
 wordTableExpression returns [Expression expr = null]
 	:
 	id = Identifier
@@ -2456,6 +2465,15 @@
 	{expr = ExpressionFactory.createRessourceReference(path);}
 	;
 
+wordTableOrStringExpression returns [Expression expr = null]
+	:
+	(stringExpression)=>id = stringExpression
+	{expr = ExpressionFactory.createTableVariableReference(id);}
+	|
+	e = wordTableExpression
+	{expr = e;}
+	;
+
 //seems OK
 numberExpression returns [Expression expr = null]
 @init {
diff --git a/ruta-ep-ide/src/main/java/org/apache/uima/ruta/ide/parser/ast/ExpressionFactory.java b/ruta-ep-ide/src/main/java/org/apache/uima/ruta/ide/parser/ast/ExpressionFactory.java
index 0b2cac9..70bd847 100644
--- a/ruta-ep-ide/src/main/java/org/apache/uima/ruta/ide/parser/ast/ExpressionFactory.java
+++ b/ruta-ep-ide/src/main/java/org/apache/uima/ruta/ide/parser/ast/ExpressionFactory.java
@@ -281,6 +281,17 @@
   public static Expression createTableVariableReference(Token id) {
     return newVariableReference(id, RutaTypeConstants.RUTA_TYPE_WT);
   }
+  
+  public static Expression createListVariableReference(Expression ref) {
+    int bounds[] = getSurroundingBounds(ref);
+    return new RutaVariableReference(bounds[0], bounds[1], "", RutaTypeConstants.RUTA_TYPE_WL);
+  }
+  
+  public static Expression createTableVariableReference(Expression ref) {
+    int bounds[] = getSurroundingBounds(ref);
+    return new RutaVariableReference(bounds[0], bounds[1], "", RutaTypeConstants.RUTA_TYPE_WT);
+  }
+  
 
   public static Expression createRessourceReference(Token path) {
     int bounds[] = getBounds(path);
@@ -428,5 +439,7 @@
     return new NullExpression(bounds[0], bounds[1]);
   }
 
+  
+
  
 }