IEC 62766-5-2:2017(E) specifies a profile of HTML5, CSS and other related web technologies for connected TVs. Its goal is to describe a common profile that can be relied on by content and service providers and implemented by manufacturers. It does not describe extensions or modification to any of the referenced technologies but only tries to define a subset of web standards that are suitable and useful for TV deployments and at the same time stable enough to provide a good degree of confidence that real interoperability can be achieved. It may add clarifications and/or additional constraints where these are needed due to the nature of the target deployment environment.