diff --git a/src/ooxml/java/org/apache/poi/xssf/eventusermodel/XSSFSheetXMLHandler.java b/src/ooxml/java/org/apache/poi/xssf/eventusermodel/XSSFSheetXMLHandler.java
index 424ff1b91..49c966a31 100644
--- a/src/ooxml/java/org/apache/poi/xssf/eventusermodel/XSSFSheetXMLHandler.java
+++ b/src/ooxml/java/org/apache/poi/xssf/eventusermodel/XSSFSheetXMLHandler.java
@@ -16,7 +16,7 @@
 ==================================================================== */
 package org.apache.poi.xssf.eventusermodel;
 
-import static org.apache.poi.xssf.usermodel.XSSFRelation.SPREADSHEETML_NS;
+import static org.apache.poi.xssf.usermodel.XSSFRelation.NS_SPREADSHEETML;
 
 import java.util.LinkedList;
 import java.util.Queue;
@@ -191,7 +191,7 @@ public class XSSFSheetXMLHandler extends DefaultHandler {
    public void startElement(String uri, String localName, String qName,
                             Attributes attributes) throws SAXException {
 
-       if (uri != null && ! uri.equals(SPREADSHEETML_NS)) {
+       if (uri != null && ! uri.equals(NS_SPREADSHEETML)) {
            return;
        }
 
@@ -297,7 +297,7 @@ public class XSSFSheetXMLHandler extends DefaultHandler {
    public void endElement(String uri, String localName, String qName)
            throws SAXException {
 
-       if (uri != null && ! uri.equals(SPREADSHEETML_NS)) {
+       if (uri != null && ! uri.equals(NS_SPREADSHEETML)) {
            return;
        }
 
diff --git a/src/ooxml/java/org/apache/poi/xssf/model/SharedStringsTable.java b/src/ooxml/java/org/apache/poi/xssf/model/SharedStringsTable.java
index 6f5d5bc32..5280cb205 100644
--- a/src/ooxml/java/org/apache/poi/xssf/model/SharedStringsTable.java
+++ b/src/ooxml/java/org/apache/poi/xssf/model/SharedStringsTable.java
@@ -18,7 +18,7 @@
 package org.apache.poi.xssf.model;
 
 import static org.apache.poi.POIXMLTypeLoader.DEFAULT_XML_OPTIONS;
-import static org.apache.poi.xssf.usermodel.XSSFRelation.SPREADSHEETML_NS;
+import static org.apache.poi.xssf.usermodel.XSSFRelation.NS_SPREADSHEETML;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -91,7 +91,7 @@ public class SharedStringsTable extends POIXMLDocumentPart {
         options.put( XmlOptions.SAVE_INNER );
      	options.put( XmlOptions.SAVE_AGGRESSIVE_NAMESPACES );
      	options.put( XmlOptions.SAVE_USE_DEFAULT_NAMESPACE );
-        options.setSaveImplicitNamespaces(Collections.singletonMap("", SPREADSHEETML_NS));
+        options.setSaveImplicitNamespaces(Collections.singletonMap("", NS_SPREADSHEETML));
     }
 
     public SharedStringsTable() {
diff --git a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFChart.java b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFChart.java
index f6d683461..ae63f235d 100644
--- a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFChart.java
+++ b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFChart.java
@@ -63,9 +63,6 @@ import org.w3c.dom.Text;
 
 /**
  * Represents a SpreadsheetML Chart
- * @author Nick Burch
- * @author Roman Kashitsyn
- * @author Martin Andersson
  */
 public final class XSSFChart extends POIXMLDocumentPart implements Chart, ChartAxisFactory {
 
diff --git a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFDrawing.java b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFDrawing.java
index 1ce809fa2..27ef139b0 100644
--- a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFDrawing.java
+++ b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFDrawing.java
@@ -52,8 +52,6 @@ import org.openxmlformats.schemas.drawingml.x2006.spreadsheetDrawing.STEditAs;
 
 /**
  * Represents a SpreadsheetML drawing
- *
- * @author Yegor Kozlov
  */
 public final class XSSFDrawing extends POIXMLDocumentPart implements Drawing {
     /**
@@ -62,8 +60,8 @@ public final class XSSFDrawing extends POIXMLDocumentPart implements Drawing {
     private CTDrawing drawing;
     private long numOfGraphicFrames = 0L;
     
-    protected static final String NAMESPACE_A = "http://schemas.openxmlformats.org/drawingml/2006/main";
-    protected static final String NAMESPACE_C = "http://schemas.openxmlformats.org/drawingml/2006/chart";
+    protected static final String NAMESPACE_A = XSSFRelation.NS_DRAWINGML;
+    protected static final String NAMESPACE_C = XSSFRelation.NS_CHART;
 
     /**
      * Create a new SpreadsheetML drawing
diff --git a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFRelation.java b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFRelation.java
index de49e8025..ac2f83567 100644
--- a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFRelation.java
+++ b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFRelation.java
@@ -352,7 +352,9 @@ public final class XSSFRelation extends POIXMLRelation {
             null
     );
     
-    public static final String SPREADSHEETML_NS = "http://schemas.openxmlformats.org/spreadsheetml/2006/main";
+    public static final String NS_SPREADSHEETML = "http://schemas.openxmlformats.org/spreadsheetml/2006/main";
+    public static final String NS_DRAWINGML = "http://schemas.openxmlformats.org/drawingml/2006/main";
+    public static final String NS_CHART = "http://schemas.openxmlformats.org/drawingml/2006/chart";
 
     private XSSFRelation(String type, String rel, String defaultName, Class<? extends POIXMLDocumentPart> cls) {
         super(type, rel, defaultName, cls);
diff --git a/src/ooxml/testcases/org/apache/poi/xssf/extractor/TestXSSFImportFromXML.java b/src/ooxml/testcases/org/apache/poi/xssf/extractor/TestXSSFImportFromXML.java
index 51a5074f6..626e104a0 100644
--- a/src/ooxml/testcases/org/apache/poi/xssf/extractor/TestXSSFImportFromXML.java
+++ b/src/ooxml/testcases/org/apache/poi/xssf/extractor/TestXSSFImportFromXML.java
@@ -17,7 +17,7 @@
 
 package org.apache.poi.xssf.extractor;
 
-import static org.apache.poi.xssf.usermodel.XSSFRelation.SPREADSHEETML_NS;
+import static org.apache.poi.xssf.usermodel.XSSFRelation.NS_SPREADSHEETML;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
@@ -98,7 +98,7 @@ public class TestXSSFImportFromXML {
     		String cellC8 = "c8";
     		String cellC9 = "c9";
     		
-    		String testXML = "<ns1:MapInfo xmlns:ns1=\""+SPREADSHEETML_NS+"\" SelectionNamespaces=\"\">" +
+    		String testXML = "<ns1:MapInfo xmlns:ns1=\""+NS_SPREADSHEETML+"\" SelectionNamespaces=\"\">" +
     						 "<ns1:Schema ID=\""+cellC6+"\" SchemaRef=\"a\" />"+ 
     						 "<ns1:Schema ID=\""+cellC7+"\" SchemaRef=\"b\" />"+ 
     						 "<ns1:Schema ID=\""+cellC8+"\" SchemaRef=\"c\" />"+ 
@@ -143,7 +143,7 @@ public class TestXSSFImportFromXML {
     		int count = 21;
     		
     		String testXML = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\" ?>"+ 
-    						 "<ns1:table xmlns:ns1=\""+SPREADSHEETML_NS+"\" id=\""+id+"\" displayName=\""+displayName+"\" ref=\""+ref+"\">"+
+    						 "<ns1:table xmlns:ns1=\""+NS_SPREADSHEETML+"\" id=\""+id+"\" displayName=\""+displayName+"\" ref=\""+ref+"\">"+
     						 "<ns1:tableColumns count=\""+count+"\" />"+ 
     						 "</ns1:table>\u0000"; 
     		XSSFMap map = wb.getMapInfo().getXSSFMapByName("table_mapping");
diff --git a/src/ooxml/testcases/org/apache/poi/xssf/usermodel/TestXSSFComment.java b/src/ooxml/testcases/org/apache/poi/xssf/usermodel/TestXSSFComment.java
index 412095846..717fc4e6b 100644
--- a/src/ooxml/testcases/org/apache/poi/xssf/usermodel/TestXSSFComment.java
+++ b/src/ooxml/testcases/org/apache/poi/xssf/usermodel/TestXSSFComment.java
@@ -17,7 +17,7 @@
 
 package org.apache.poi.xssf.usermodel;
 
-import static org.apache.poi.xssf.usermodel.XSSFRelation.SPREADSHEETML_NS;
+import static org.apache.poi.xssf.usermodel.XSSFRelation.NS_SPREADSHEETML;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertSame;
@@ -147,7 +147,7 @@ public final class TestXSSFComment extends BaseTestCellComment  {
 
         CTComment ctComment = comment.getCTComment();
         XmlObject[] obj = ctComment.selectPath(
-                "declare namespace w='"+SPREADSHEETML_NS+"' .//w:text");
+                "declare namespace w='"+NS_SPREADSHEETML+"' .//w:text");
         assertEquals(1, obj.length);
         assertEquals(TEST_RICHTEXTSTRING, comment.getString().getString());
 
@@ -165,7 +165,7 @@ public final class TestXSSFComment extends BaseTestCellComment  {
         //check the low-level stuff
         comment.setString(richText);
         obj = ctComment.selectPath(
-                "declare namespace w='"+SPREADSHEETML_NS+"' .//w:text");
+                "declare namespace w='"+NS_SPREADSHEETML+"' .//w:text");
         assertEquals(1, obj.length);
         assertSame(comment.getString(), richText);
         //check that the rich text is set in the comment