The Ks-signal system (Ks represents combined signal) is since 1993 the German Federal Railways and Deutsche Reichsbahn used at the former. There come signals applications that combine the advantages and / or main signal function in a signal screen. They gradually replace under interlocking Neubauten the old H / V light and semaphore signals Hl signals and the signals Sv.If you want to know more here is the link to the wiki.https://de.wikipedia.org/wiki/Ks-Signalsystem