Index: /FCKeditor/trunk/_whatsnew.html
===================================================================
--- /FCKeditor/trunk/_whatsnew.html	(revision 1377)
+++ /FCKeditor/trunk/_whatsnew.html	(revision 1378)
@@ -48,4 +48,9 @@
 		<li>[<a target="_blank" href="http://dev.fckeditor.net/ticket/1522">#1522</a>] The ENTER
 			key will now work properly in IE with the cursor at the start of a formatted block.</li>
+		<li>[<a target="_blank" href="http://dev.fckeditor.net/ticket/1503">#1503</a>] It's possible
+			to define in the Styles that a Style (with an empty class) must be shown selected
+			only when no class is present in the current element, and selecting that item will 
+			clear the current class (it does apply to any attribute, not only classes).</li>
+
 	</ul>
 	<p>
Index: /FCKeditor/trunk/editor/_source/classes/fckstyle.js
===================================================================
--- /FCKeditor/trunk/editor/_source/classes/fckstyle.js	(revision 1377)
+++ /FCKeditor/trunk/editor/_source/classes/fckstyle.js	(revision 1378)
@@ -232,6 +232,7 @@
 						this._RemoveOverrides( pathElement, styleOverrides[ pathElementName ] ) ;
 
-						// Remove the element if no more attributes are available.
-						this._RemoveNoAttribElement( pathElement ) ;
+						// Remove the element if no more attributes are available and it's an inline style element
+						if ( this.GetType() == FCK_STYLE_INLINE)
+							this._RemoveNoAttribElement( pathElement ) ;
 					}
 				}
@@ -487,5 +488,5 @@
 		{
 			case FCK_STYLE_BLOCK :
-				return this.CheckElementRemovable( elementPath.Block || elementPath.BlockLimit ) ;
+				return this.CheckElementRemovable( elementPath.Block || elementPath.BlockLimit, true ) ;
 
 			case FCK_STYLE_INLINE :
@@ -689,5 +690,6 @@
 		}
 
-		return ( valueA == valueB )
+		// Return true if they match or if valueA is null and valueB is an empty string
+		return ( valueA == valueB || ( ( valueA === null || valueA === '' ) && ( valueB === null || valueB === '' ) ) )
 	},