Which of the following is NOT a way to incorporate classified source material?

The correct answer is found in the notion that "planning" is not a method for incorporating classified source material. Incorporating classified material usually involves specific processes aimed at ensuring the information is handled correctly and protected according to relevant standards. This includes accurately summarizing any classified details, adhering to proper classification guidelines, and consulting with classification authorities when needed to clarify the use and handling of such materials.

Planning, while essential in the overall management of projects involving classified information, does not directly pertain to the mechanisms of incorporating classified information. It refers more to the strategic aspect of preparing for tasks rather than the act of utilizing the classified content itself. Therefore, it stands apart from the other methods listed, which are concrete practices involved in the proper use and dissemination of classified source material.