The Rich Communication Services program is a GSM Association (GSMA) program for the creation of inter-operator communication services based on IP Multimedia Subsystem (IMS). It is marketed by the GSMA under the brand name joyn.Key features of RCS include: Enhanced Phonebook: service capabilities and enhanced contacts information such as presence and service discovery. Enhanced Messaging: enables a large variety of messaging options including chat, emoticons, location share and file sharing.