Final answer:
Marks below 3.0 on an E7 through E9 performance evaluation require substantiation in the comments block to provide context and justification.
Step-by-step explanation:
On the E7 through E9 performance evaluation, the marks that require substantiation in the comments block are marks below 3.0.
This means that if an individual receives a mark below 3.0, it needs to be accompanied by comments explaining the reasons for such a low score.
This is done to provide context and justification for the evaluation.