diff --git a/src/java/org/apache/poi/hssf/usermodel/HSSFDataValidationHelper.java b/src/java/org/apache/poi/hssf/usermodel/HSSFDataValidationHelper.java
index a6990f3e2..15161cb88 100644
--- a/src/java/org/apache/poi/hssf/usermodel/HSSFDataValidationHelper.java
+++ b/src/java/org/apache/poi/hssf/usermodel/HSSFDataValidationHelper.java
@@ -27,11 +27,12 @@ import org.apache.poi.ss.util.CellRangeAddressList;
  * Helper for working with Data Validation
  */
 public class HSSFDataValidationHelper implements DataValidationHelper {
-	//URF_UNREAD_FIELD
+	// Findbugs: URF_UNREAD_FIELD . Do not delete without understanding how this class works.
 	//private HSSFSheet sheet;
 	
 	public HSSFDataValidationHelper(HSSFSheet sheet) {
 		super();
+		// Findbugs: URF_UNREAD_FIELD . Do not delete without understanding how this class works.
 		//this.sheet = sheet;
 	}
 
diff --git a/src/java/org/apache/poi/hssf/usermodel/HSSFTextbox.java b/src/java/org/apache/poi/hssf/usermodel/HSSFTextbox.java
index 0dd4533e3..d1e8b9ffa 100644
--- a/src/java/org/apache/poi/hssf/usermodel/HSSFTextbox.java
+++ b/src/java/org/apache/poi/hssf/usermodel/HSSFTextbox.java
@@ -48,7 +48,7 @@ public class HSSFTextbox extends HSSFSimpleShape {
         super(spContainer, objRecord, textObjectRecord);
     }
 
-    //Unused: URF_UNREAD_FIELD
+    // Findbugs: URF_UNREAD_FIELD. Do not delete without understanding how this class works.
     //HSSFRichTextString string = new HSSFRichTextString("");
 
     /**
diff --git a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFDataValidationHelper.java b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFDataValidationHelper.java
index 98b2a84d7..8f7908dbd 100644
--- a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFDataValidationHelper.java
+++ b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFDataValidationHelper.java
@@ -35,12 +35,13 @@ import org.openxmlformats.schemas.spreadsheetml.x2006.main.STDataValidationType;
  *
  */
 public class XSSFDataValidationHelper implements DataValidationHelper {
-    //Unused: URF_UNREAD_FIELD
+	// Findbugs: URF_UNREAD_FIELD. Do not delete without understanding how this class works.
 	//private XSSFSheet xssfSheet;
 	
     
     public XSSFDataValidationHelper(XSSFSheet xssfSheet) {
 		super();
+		// Findbugs: URF_UNREAD_FIELD. Do not delete without understanding how this class works.
 		//this.xssfSheet = xssfSheet;
 	}
 
diff --git a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFGraphicFrame.java b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFGraphicFrame.java
index 4c0811f79..e0bbc266b 100644
--- a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFGraphicFrame.java
+++ b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFGraphicFrame.java
@@ -43,8 +43,8 @@ public final class XSSFGraphicFrame extends XSSFShape {
 	private static CTGraphicalObjectFrame prototype = null;
 
 	private CTGraphicalObjectFrame graphicFrame;
-	// Unused: URF_UNREAD_FIELD
-	//private XSSFDrawing drawing;
+	// FIXME: shadows protected XSSFShape.drawing
+	private XSSFDrawing drawing;
 	private XSSFClientAnchor anchor;
 
 	/**