(25)In the course of providing services under this Regulation, external reviewers should give an independent opinion on whether the issuer has aligned with the taxonomy requirements. When assessing the alignment with quantitative criteria, external reviewers should verify that any forward-looking estimates are based on reasonable assumptions, without giving guarantees on outcomes. When assessing the alignment with qualitative criteria, external reviewers should verify the existence of appropriate processes and due diligence systems designed to assess, mitigate and remedy risks and other issues that might arise in relation to those criteria.