ShellBrowser Delphi Components Documentation
Occurs, whenever a new item is added to a JamSystemShellView.
By writing an OnAddItem event handler, you can decide individually which items should be shown in the JamSystemShellView by changing the CanAdd variable.
This event is not fired inside Windows 7 libraries folders. It is based on the Windows API callback ICommDlgBrowser::IncludeObject which seems to be not fired in such a case, see also this discussion.