The Compendium of Principles and Recommendations on Inclusion, Equity, and Diversity, developed under Work Package 2 (WP2) of the Erasmus+ IncluDE project, presents a comprehensive framework of principles and actionable recommendations to promote inclusion, equity, and diversity across higher education and lifelong learning. It addresses a wide spectrum of inclusion challenges through a multi-level approach encompassing macro (policy), meso (institutional), and micro (practice) dimensions. Based on a Systematic review of recent research on best practices, national and international policies, and institutional guidelines, it provides guiding policy and pedagogical principles, as well as specific actionable recommendations for improving inclusion. The diagnostic tools and monitoring instruments provided establish a Reference Framework for higher education institutions (HEIs) to assess and improve their inclusion policies, thus supporting the development of inclusive environments across both on-site and distance learning contexts.