This document specifies the "Fast Service Announcement Protocol" (FSAP) for general purposes in ITS by reference to ISO/TS 16460:2016, supporting all features of ISO/TS 16460:2016, especially supporting also the Service Response Message (SRM) and related features in addition to the Service Announcement Message (SAM) that enables only very basic features. FSAP is in support of locally advertised ITS services uniquely identified by an ITS application identifier (ITS-AID). This document specifies message formats and related basic protocol procedures by reference to ISO/TS 16460:2016, and further related protocol requirements for operation of FSAP in the context of an ITS station specified in ISO 21217:2014. This document illustrates its relations to service announcement protocols specified by ETSI TC ITS and IEEE WG 1609.