Digital S was the choice format of the Fox network in the late 1990s. One of it's attributes is it supported 480P which was how Fox introduced Digital TV. (they are 720P today). Other than Fox and some of it's affiliates, the format did not have wide spread use. It's competitor was Sony Betacam SX which was more widely adopted due to analog Betacam playback capability. Both these digital formats used rather high compression ratios by broadcast standards of the time. They were intended as news gathering and other lower quality applications.