Final answer:
Without further information, it is not possible to identify specific activities that City employees need not report to the Commissioner of Investigation or an Inspector General.
Step-by-step explanation:
The Mayor's Executive Order #16 outlines the activities that City employees must report to the Commissioner of Investigation or an Inspector General. To determine which activities need not be reported, it is necessary to review the specific details of the Executive Order, which are not provided in the question. Therefore, without further information, it is not possible to identify specific activities that need not be reported.