Final answer:
Personal opinions are not required to be maintained in the Division Officer's Notebook, which should contain official records like duty assignments, training schedules, and maintenance records.
Step-by-step explanation:
The information that is NOT required to be maintained in the Division Officer's Notebook is C. Personal opinions. The Division Officer's Notebook should consist of factual and relevant information concerning the personnel and operations of a naval division. It traditionally includes Personnel duty assignments, Training schedules, and Maintenance records, as these are all official records that assist in the management and administration of the division. Personal opinions do not belong in this professional setting, as they can be subjective and may not reflect official Navy policy or the professional conduct expected within this context.