Starts a drag-and-drop-add operation. When the mouse is over a legal drop spot, the cursor will change into the drop-add cursor, allowing you to copy the text to a new location. At the completion of a drag-and-drop-add operation, the text will be copied to the dropped location. If there is no primary selection, this command has no effect.
By default this command is executed by left-clicking and dragging selected text, while holding down the control key. If the control key is pressed during any point during a drag-and-drop operation, the operation will turn into a drag-and-drop-add operation.
Warning: This command must be followed by a SelectionDrop. See SelectionDrop and SelectionStartDragAdd above.