diff --git a/pmd-vm/pmd-vm-checkstyle-suppressions.xml b/pmd-vm/pmd-vm-checkstyle-suppressions.xml
index e9b7fd4134..2a19a99af3 100644
--- a/pmd-vm/pmd-vm-checkstyle-suppressions.xml
+++ b/pmd-vm/pmd-vm-checkstyle-suppressions.xml
@@ -1,12 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE suppressions PUBLIC
-     "-//Puppy Crawl//DTD Suppressions 1.0//EN"
-     "http://www.puppycrawl.com/dtds/suppressions_1_0.dtd">
+    "-//Checkstyle//DTD SuppressionFilter Configuration 1.2//EN"
+    "https://checkstyle.org/dtds/suppressions_1_2.dtd">
 <suppressions>
     <suppress files="[\\/]generated-sources[\\/]" checks="[a-zA-Z0-9]*"/>
 
     <!-- The velocity language is under the Apache License. -->
-    <suppress checks="RegexpHeaderCheck" files="net[\\/]sourceforge[\\/]pmd[\\/]lang[\\/]vm[\\/].*"/>
-
-    <suppress checks="ModifiedControlVariable" files="src[\\/]main[\\/]java[\\/]net[\\/]sourceforge[\\/]pmd[\\/]lang[\\/]vm[\\/]ast[\\/]NodeUtils\.java"/>
+    <suppress checks="RegexpHeader" files="ast[\\/](ASTDirective|AbstractVmNode|ASTDivNode|ASTSubtractNode|NodeUtils|ASTMulNode|ASTMethod|ASTStringLiteral|ASTModNode|ASTEscape|ASTReference|ASTAddNode|ASTMathNode)\.java"/>
 </suppressions>
\ No newline at end of file
diff --git a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTAddNode.java b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTAddNode.java
index 05433404d7..d2db41022e 100644
--- a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTAddNode.java
+++ b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTAddNode.java
@@ -21,10 +21,9 @@ package net.sourceforge.pmd.lang.vm.ast;
  */
 
 /**
- * Handles number addition of nodes.<br>
- * <br>
+ * Handles number addition of nodes.
  *
- * Please look at the Parser.jjt file which is what controls the generation of
+ * <p>Please look at the Parser.jjt file which is what controls the generation of
  * this class.
  *
  * @author <a href="mailto:wglass@forio.com">Will Glass-Husain</a>
diff --git a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTDirective.java b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTDirective.java
index 39c5639a54..28bb07501e 100644
--- a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTDirective.java
+++ b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTDirective.java
@@ -27,9 +27,9 @@ import java.util.Set;
 /**
  * This class is responsible for handling the pluggable directives in VTL.
  *
- * For example : #foreach()
+ * <p>For example : #foreach()
  *
- * Please look at the Parser.jjt file which is what controls the generation of
+ * <p>Please look at the Parser.jjt file which is what controls the generation of
  * this class.
  *
  * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
diff --git a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTDivNode.java b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTDivNode.java
index 46accb36dc..5abeb766e4 100644
--- a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTDivNode.java
+++ b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTDivNode.java
@@ -21,10 +21,9 @@ package net.sourceforge.pmd.lang.vm.ast;
  */
 
 /**
- * Handles number division of nodes<br>
- * <br>
+ * Handles number division of nodes
  *
- * Please look at the Parser.jjt file which is what controls the generation of
+ * <p>Please look at the Parser.jjt file which is what controls the generation of
  * this class.
  *
  * @author <a href="mailto:wglass@forio.com">Will Glass-Husain</a>
diff --git a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTEscape.java b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTEscape.java
index d7e5bc2b0d..1ff71481ec 100644
--- a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTEscape.java
+++ b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTEscape.java
@@ -23,7 +23,7 @@ package net.sourceforge.pmd.lang.vm.ast;
 /**
  * This class is responsible for handling Escapes in VTL.
  *
- * Please look at the Parser.jjt file which is what controls the generation of
+ * <p>Please look at the Parser.jjt file which is what controls the generation of
  * this class.
  *
  * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
@@ -31,7 +31,7 @@ package net.sourceforge.pmd.lang.vm.ast;
  */
 public final class ASTEscape extends AbstractVmNode {
 
-    /** Used by the parser */
+    /** Used by the parser. */
     private String val;
 
 
diff --git a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTMathNode.java b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTMathNode.java
index 345390def9..b8e8887bbb 100644
--- a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTMathNode.java
+++ b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTMathNode.java
@@ -20,10 +20,9 @@ package net.sourceforge.pmd.lang.vm.ast;
  */
 
 /**
- * Helps handle math<br>
- * <br>
+ * Helps handle math
  *
- * Please look at the Parser.jjt file which is what controls the generation of
+ * <p>Please look at the Parser.jjt file which is what controls the generation of
  * this class.
  *
  * @author <a href="mailto:wglass@forio.com">Will Glass-Husain</a>
diff --git a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTMethod.java b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTMethod.java
index c3856d28a5..81be247354 100644
--- a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTMethod.java
+++ b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTMethod.java
@@ -23,13 +23,12 @@ package net.sourceforge.pmd.lang.vm.ast;
 /**
  * ASTMethod.java
  *
- * Method support for references : $foo.method()
- *
- * NOTE :
+ * <p>Method support for references : $foo.method()
  *
+ * <p>NOTE :
  * introspection is now done at render time.
  *
- * Please look at the Parser.jjt file which is what controls the generation of
+ * <p>Please look at the Parser.jjt file which is what controls the generation of
  * this class.
  *
  * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
diff --git a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTModNode.java b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTModNode.java
index 770b843bb1..99064cf72d 100644
--- a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTModNode.java
+++ b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTModNode.java
@@ -21,10 +21,9 @@ package net.sourceforge.pmd.lang.vm.ast;
  */
 
 /**
- * Handles modulus division<br>
- * <br>
+ * Handles modulus division
  *
- * Please look at the Parser.jjt file which is what controls the generation of
+ * <p>Please look at the Parser.jjt file which is what controls the generation of
  * this class.
  *
  * @author <a href="mailto:wglass@forio.com">Will Glass-Husain</a>
diff --git a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTMulNode.java b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTMulNode.java
index 51cea67406..9da37f9a92 100644
--- a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTMulNode.java
+++ b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTMulNode.java
@@ -21,10 +21,9 @@ package net.sourceforge.pmd.lang.vm.ast;
  */
 
 /**
- * Handles multiplication<br>
- * <br>
+ * Handles multiplication
  *
- * Please look at the Parser.jjt file which is what controls the generation of
+ * <p>Please look at the Parser.jjt file which is what controls the generation of
  * this class.
  *
  * @author <a href="mailto:wglass@forio.com">Will Glass-Husain</a>
diff --git a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTReference.java b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTReference.java
index ce4931f900..c36490962a 100644
--- a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTReference.java
+++ b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/ASTReference.java
@@ -23,7 +23,7 @@ package net.sourceforge.pmd.lang.vm.ast;
 /**
  * This class is responsible for handling the references in VTL ($foo).
  *
- * Please look at the Parser.jjt file which is what controls the generation of
+ * <p>Please look at the Parser.jjt file which is what controls the generation of
  * this class.
  *
  * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
@@ -47,7 +47,7 @@ public final class ASTReference extends AbstractVmNode {
     }
 
     /**
-     * Returns the 'root string', the reference key
+     * Returns the 'root string', the reference key.
      *
      * @return the root string.
      */
@@ -61,7 +61,7 @@ public final class ASTReference extends AbstractVmNode {
      * literal of the calling arg to make it work nicely when calling arg is
      * null. It seems a bit much, but does keep things consistant.
      *
-     * Note, you can only set the literal once...
+     * <p>Note, you can only set the literal once...
      *
      * @param literal
      *            String to render to when null
diff --git a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/AbstractVmNode.java b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/AbstractVmNode.java
index 717db05be2..9c1d69ada7 100644
--- a/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/AbstractVmNode.java
+++ b/pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/AbstractVmNode.java
@@ -48,7 +48,7 @@ abstract class AbstractVmNode extends AbstractJjtreeNode<VmNode> implements VmNo
     public String literal() {
         // if we have only one string, just return it and avoid
         // buffer allocation. VELOCITY-606
-        if (getFirstToken() != null && firstToken.equals(getLastToken())) {
+        if (getFirstToken() != null && getFirstToken().equals(getLastToken())) {
             return NodeUtils.tokenLiteral(getFirstToken());
         }
 
diff --git a/pmd-vm/src/test/java/net/sourceforge/pmd/LanguageVersionTest.java b/pmd-vm/src/test/java/net/sourceforge/pmd/LanguageVersionTest.java
index 9856fe978b..9fbd65f8a1 100644
--- a/pmd-vm/src/test/java/net/sourceforge/pmd/LanguageVersionTest.java
+++ b/pmd-vm/src/test/java/net/sourceforge/pmd/LanguageVersionTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
  */
 
diff --git a/pmd-vm/src/test/java/net/sourceforge/pmd/RuleSetFactoryTest.java b/pmd-vm/src/test/java/net/sourceforge/pmd/RuleSetFactoryTest.java
index 0acec6a8a7..e0ae0ae307 100644
--- a/pmd-vm/src/test/java/net/sourceforge/pmd/RuleSetFactoryTest.java
+++ b/pmd-vm/src/test/java/net/sourceforge/pmd/RuleSetFactoryTest.java
@@ -1,11 +1,11 @@
-/**
+/*
  * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
  */
 
 package net.sourceforge.pmd;
 
 /**
- * Test velocity's rulesets
+ * Test velocity's rulesets.
  */
 public class RuleSetFactoryTest extends AbstractRuleSetFactoryTest {
     // no additional tests yet
diff --git a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/VmParserTest.java b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/VmParserTest.java
index 5956adfa63..5a9fa53587 100644
--- a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/VmParserTest.java
+++ b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/VmParserTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
  */
 
diff --git a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/ast/VmParsingHelper.java b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/ast/VmParsingHelper.java
index c7f6a9657c..00a2319c63 100644
--- a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/ast/VmParsingHelper.java
+++ b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/ast/VmParsingHelper.java
@@ -1,4 +1,4 @@
-/**
+/*
  * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
  */
 
diff --git a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/bestpractices/AvoidReassigningParametersTest.java b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/bestpractices/AvoidReassigningParametersTest.java
index b02ee8345a..f2ad8234e9 100644
--- a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/bestpractices/AvoidReassigningParametersTest.java
+++ b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/bestpractices/AvoidReassigningParametersTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
  */
 
diff --git a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/bestpractices/UnusedMacroParameterTest.java b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/bestpractices/UnusedMacroParameterTest.java
index feab866273..7c21276a2a 100644
--- a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/bestpractices/UnusedMacroParameterTest.java
+++ b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/bestpractices/UnusedMacroParameterTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
  */
 
diff --git a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/AvoidDeeplyNestedIfStmtsTest.java b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/AvoidDeeplyNestedIfStmtsTest.java
index 84038b3337..6fabea1dda 100644
--- a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/AvoidDeeplyNestedIfStmtsTest.java
+++ b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/AvoidDeeplyNestedIfStmtsTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
  */
 
diff --git a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/CollapsibleIfStatementsTest.java b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/CollapsibleIfStatementsTest.java
index f3a83a7e5a..09e81ec347 100644
--- a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/CollapsibleIfStatementsTest.java
+++ b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/CollapsibleIfStatementsTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
  */
 
diff --git a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/ExcessiveTemplateLengthTest.java b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/ExcessiveTemplateLengthTest.java
index 2394b02fc9..b37cdfeb19 100644
--- a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/ExcessiveTemplateLengthTest.java
+++ b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/ExcessiveTemplateLengthTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
  */
 
diff --git a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/NoInlineJavaScriptTest.java b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/NoInlineJavaScriptTest.java
index 90e87c5438..6e1bbc8620 100644
--- a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/NoInlineJavaScriptTest.java
+++ b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/NoInlineJavaScriptTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
  */
 
diff --git a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/NoInlineStylesTest.java b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/NoInlineStylesTest.java
index ed09b4024f..244567d2fd 100644
--- a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/NoInlineStylesTest.java
+++ b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/design/NoInlineStylesTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
  */
 
diff --git a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/errorprone/EmptyForeachStmtTest.java b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/errorprone/EmptyForeachStmtTest.java
index c21a43f244..9429d3cdf2 100644
--- a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/errorprone/EmptyForeachStmtTest.java
+++ b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/errorprone/EmptyForeachStmtTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
  */
 
diff --git a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/errorprone/EmptyIfStmtTest.java b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/errorprone/EmptyIfStmtTest.java
index be82d1bb85..2583b7581b 100644
--- a/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/errorprone/EmptyIfStmtTest.java
+++ b/pmd-vm/src/test/java/net/sourceforge/pmd/lang/vm/rule/errorprone/EmptyIfStmtTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
  */