An Ad Hoc User task is a task list containing actions and rules that a user can choose to perform in a client. Ad hoc user tasks are assigned user group security and this is used to control the ad hoc tasks that should appear in the clients for a particular user.
Note:
Tasks can be executed on multiple items at the same time. To select consecutive items, click the first item, hold the Shift key and click the last item. To select specific items, hold the Ctrl key while clicking the items. The tasks you execute apply to the selected items.