Joint Indexing of content and jump to other service included as is presence of each other’s main service live stream on the alternative platform, so Das Erste live on the ZDF platform and vice-versa.
East Midlands Today
London Lite gave kudos
According to https://www.satellifax.de/pda/mlesen.php?id=8493cbcf35f09a8719807bfde718f462
..the linking was due to start at 12noon (CET).
But only on browser, not apps.