Disclosing peer review results
Additionally to what Buffy wrote, there are many issues arising with predatory journals stating that they are doing peer review when they actually are just pocketing author publishing charges. If you get any peer review from these journals, it is usually just something non-committal (&quot;Nice work!&quot;). So submitting your peer-review will show that actual peer-review took place.
I try to engage with papers I am reviewing, asking lots of questions that pop up. And I correct comma errors, which seem to be so prevalent these days ;)