This document provides a guide for entities that participate in the distribution of funds that include compliance with the DNSH principle) as a condition. The objective is to facilitate the design and evaluation of actions following the compliance criteria of the aforementioned principle. It takes as a framework the European funds associated with Regulation (EU) 2021/241, which establishes the Recovery and Resilience Mechanism. However, the guidelines included may be useful for different frameworks, such as the regulation of common provisions [Regulation (EU) 2021/1060 of the European Parliament and of the Council, of June 24, 2021], which applies, among others, to the European Regional Development Fund and the Fund for Maritime, Fisheries and Aquaculture Policies, and includes the need to comply with the DNSH principle also for these funds. These guidelines can be useful both for entities that intend to demonstrate compliance with the DNSH principle and for those that are in charge of validating or verifying it. As a complement to these recommendations, an annex of self-assessment examples has been included. For industrial sectors whose facilities are within the Emissions Trading Scheme (ETS), self-assessing and justifying compliance with the principle is a special challenge. These sectors are on the list identified by the European Commission of activities that must meet a series of strict conditions in order to be considered in accordance with the principle of not harming the environment, since, a priori, they are considered ineligible. Due to this, and taking into account that it will be the managing body of the aid program that will evaluate on a case-by-case basis whether the action complies with such conditions, it has been considered a great risk to provide recommendations or justification examples in this document, which may not be valid for its application, since each project in this area implies a particular situation. On the other hand, this guide should be used as a complement to the regulations and other reference documents that the different management units have been publishing ).