Final answer:
Detachment of reporting senior reports for E1-E6 are optional evaluation reports known as FITREPS or DIP reports and submitted using the NAVPERS 1616/26 form.
Step-by-step explanation:
The detachment of reporting senior reports that are optional for enlisted personnel in the paygrades E1-E6 in the United States Navy are known as FITREPS or evaluation reports. These reports are submitted using the form NAVPERS 1616/26, commonly referred to as "Detachment of Individual Personnel (DIP) reports". While these reports are not mandatory, they are highly encouraged as they can be beneficial for a service member's career progression and for the reporting senior's record keeping. If a reporting senior chooses to submit a DIP report, it should include information relevant to the member's performance, character, and command impact during the reporting period.