Final answer:
The report on a captain by a concurrent reporting senior who is also a captain or below requires an additional endorsement from a senior rater who is a major or above.
Step-by-step explanation:
When a captain or individual of a lower rank who is in the same competitive category endorses a report on another captain, the report requires an additional endorsement from a senior rater who is a major or above. This is necessary to ensure that the report on the captain is reviewed and endorsed by someone of a higher rank and potentially with broader perspective within the organization or command structure. The additional endorsement ensures objectivity and proper oversight in the evaluation process.