How are outliers determined in DEseq2?

I have aligned my samples using STAR and did differential expression analysis with DEseq2. In the output there are options to view different "statuses." Low (Mean count value less than 10), OK (Mean count value higher than 10), and Outlier.

It is not entirely clear how Outliers are determined. Does anyone know?

I have used multiple alignment and differential expression analyses and this pipeline yields the smallest number of significant genes in DE. But many of the genes that show up in the Outliers list are significant in other analyses.

Thanks!