What is "av.link"

AV.link, also known under the trade names nexTViewLink, SmartLink, Q-Link, EasyLink, etc., is a protocol to carry control information between audio-visual devices connected via the SCART (EIA Multiport) connector.

It is standardised as CENELEC EN 50157-1.

The Consumer Electronics Control (CEC) communication channel in HDMI and PDMI is based on AV.link.