Clears the source item URL if the item results from a copy operation.
Assembly: Microsoft.SharePoint (in Microsoft.SharePoint.dll)
Available in Sandboxed Solutions: Yes
Available in SharePoint Online
Using this method is equivalent to clicking Unlink from Source on the View Properties page, but not removing the Copy Destination from the source item.
If the item results from a copy operation, the CopySource property contains the URL of the source item, and this method clears this URL.