Recommendation ITU-T H.770 describes the mechanisms for service provider discovery, service discovery and selection for Internet protocol television (IPTV) services. The mechanisms enable IPTV terminal devices to provide the end-users with effective ways for consuming IPTV services.The expected types of IPTV services using service discovery information include linear television (TV),video on demand (VoD),etc.This Recommendation identifies service discovery metadata elements and attributes providing information concerning service providers and contents/services, and its delivery protocols covering both unicast and multicast transport mechanisms.This 2015 edition of the Recommendation adds notes on how to treat "Web Portal URL" in clause 7.1.It also modifies the examples of "Portal URL" and "Metadata server URL",changing those into"://[:]/".In clause 10 it also adds a text to show the example on "Metadata server URL". Moreover,"Preferred Content Guide Discovery record Location" is changed into "Preferred Content Guide Discovery record" in clauses 10.1 and 10.2, and its example has been changed to a Boolean value.Relevant elements/attributes in Appendix II are also changed.This edition of the Recommendation also adds a new service type,"Widget service",to Table 7.1-4.