To create an Ad Hoc Conference call, click the Add Participant tab at the bottom of the call window.
In the Add Participant tab, select a person to add from the selected directory and then click the Connect button to call them.
On the Connecting screen, you can make sure that the person you're adding answers the call and is properly connected. You can also talk to them one-on-one during this portion of the call. This gives you the opportunity to explain the purpose of the call to the person you are adding, so that they are not immediately added to an Ad Hoc Conference already in progress.
Once the person you added answers the call, the Conference button will activate. Click the Conference button to complete the process. You are now in an Ad Hoc Conference, and will see the Participant List tab for the call.
Note: the Participant List tab replaces the Transfer tab for the duration of your call because Ad Hoc Conferences are not transferable. You can still add more participants to your Ad Hoc Conference by returning to the Add Participant tab and repeating this process.