Book excerpt: Geographical indications represent a powerful way to foster sustainable food systems through territorial approaches and market linkages, especially for small-scale actors. In this perspective, and following the FAO publication methodologies of the origin-linked virtuous circle, local actors need to well define their geographical indication (GI) system and, more specifically, the product specifications as well as monitor and evaluate the impacts and readjust the system as necessary for the reproduction of local resources. These guidelines aim at providing a detailed and stepwise approach with specific tools to help practitioners in establishing their framework in relation with their objectives and local conditions, to help both the qualification though a prospective evaluation, and the reproduction of local resources though retrospective evaluation.