Extremely rare processes involving kaons are powerful test for the Standard Model and may eventually find signs of new physics in the upcoming years. The second Rare Kaon decays Forum is organized by the Dipartimento di Fisica "Ettore Pancini" and by INFN Sezione di Napoli. It will be hosted by Villa Orlandi (Anacapri) on Capri island. It is aimed at the collaboration of theorists and experimentalists active in the field of extremely rare processes to review the status of present knowledge, and to stimulate preparation of future initiatives in the field. Following the successful format of the first meeting of this series held in Edinburgh in 2018, aside oral presentations a significant amount of time is allocated for open discussions on specific topics.