Any Publons user can endorse a review. An endorsement shows that the endorser considers the review to be worthy of their advocacy.
Rewarding high-quality reviews is important. At the same time, we are trying to build a positive site where all contributions are welcome. So, rather than flagging bad reviews, our endorsement system rewards high-quality reviews. Endorsements increase the reviewer's merit score and so are a good way to reward quality reviews.
If you come across a review that you feel is of a high quality then you are welcome to endorse it. To do this, simply hit the '+' button on the 'Review detail' page.
We ask in particular that editors and authors consider endorsing reviews of their papers if it is merited. Here's what the relevant section of a review looks like once endorsed: