Simply add a Column to RadGrid in the GridColumn Collection Editor of the Configuration wizard. You will note that a value for FilterControlAltText is autopopulated. When you hit Ok, that value is written in the column definition, in markup. If you clear that text in the editor, then, in markup you will find the value FilterControlAltText ="". This is useless clutter, which you should manually remove from the markup. The editor/designer should remove the property entry from markup if you clear the FilterControlAltText from the PropertyGrid in the GridColumn Collection Editor.