IEC 61030
D²B is an IEC standard for a low-speed multi-master serial [communication bus] for home automation applications. It was originally developed by Philips in the 1980s. In 2006 it has been withdrawn by IEC because another standard was proposed, JTC1 SC 83/WG1. There remain many IEC61030-compliant devices, such as some Philips-branded head units and CD changers from car stereos.
The SCART connector provides a D²B connection for inter-device communication.