diff --git a/core/src/main/java/hudson/scm/SubversionTagAction.java b/core/src/main/java/hudson/scm/SubversionTagAction.java
index 74a315bb973ec2d82981515cc360083edf25ea5b..284e6958114ad5aa4c8156d02cb771f5815ca554 100644
--- a/core/src/main/java/hudson/scm/SubversionTagAction.java
+++ b/core/src/main/java/hudson/scm/SubversionTagAction.java
@@ -21,6 +21,8 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.regex.Pattern;
+import java.util.regex.Matcher;
 import java.util.Map.Entry;
 
 /**
@@ -75,6 +77,23 @@ public class SubversionTagAction extends AbstractScmTagAction {
         return Collections.unmodifiableMap(tags);
     }
 
+    private static final Pattern TRUNK_BRANCH_MARKER = Pattern.compile("/(trunk|branches)(/|$)");
+
+    /**
+     * Creates a URL, to be used as the default value of the module tag URL.
+     *
+     * @return
+     *      null if failed to guess.
+     */
+    public String makeTagURL(SvnInfo si) {
+        // assume the standard trunk/branches/tags repository layout
+        Matcher m = TRUNK_BRANCH_MARKER.matcher(si.url);
+        if(!m.find())
+            return null;    // doesn't have 'trunk' nor 'branches'
+
+        return si.url.substring(0,m.start())+"/tags/"+build.getProject().getName()+"-"+build.getNumber();
+    }
+
     /**
      * Invoked to actually tag the workspace.
      */
diff --git a/core/src/main/resources/hudson/scm/SubversionTagAction/tagForm.jelly b/core/src/main/resources/hudson/scm/SubversionTagAction/tagForm.jelly
index 8a96ca9a3f446287f94b5b4dc130616651746776..9a0c54c9c1ab192089763885d473ec79c963d05f 100644
--- a/core/src/main/resources/hudson/scm/SubversionTagAction/tagForm.jelly
+++ b/core/src/main/resources/hudson/scm/SubversionTagAction/tagForm.jelly
@@ -22,7 +22,10 @@
               <td style="white-space:nowrap;"><label for="tag${loop.index}">
                 ${m.key.url} (rev.${m.key.revision})
               </label></td>
-              <td width="100%"><input type="text" name="name${loop.index}" value="xxx" style="width:100%" id="name${loop.index}" /></td>
+              <td width="100%">
+                <input type="text" name="name${loop.index}"
+                       value="${it.makeTagURL(m.key)}" style="width:100%" id="name${loop.index}" />
+              </td>
             </tr>
           </j:forEach>
         </table>