The bi-directionality of electric vehicle (EV) charging has proved to be important for load leveling purposes, amongst others. Thus, Vehicle-to-Grid (V2G) communication protocols are a necessity which ensures that the information exchange that takes place during this process, is efficient, secure, and reliable. Several research articles regarding different V2G communication protocols have been published over the years. This paper summarizes current relevant research in this area in order to provide a reference guide for researchers interested in this subject.