The aim of this pocket guide is to bring together all relevant information about COST into an “easy to use” publication. This guide includes information on the COST structure and goals, the Open Call, the National Coordinators (contact points) and financial Instruments plus, most importantly, the COST Actions. In this issue, the Actions are presented from the most recent ones to those ending this year. In order to highlight COST’s interdisciplinary dimension, Trans-Domain Actions are presented in a separate sub-chapter. Complementary Action information can be found on the COST website.