See X/Open Directory Service (XDS).

X/Open Directory Service. In the Distributed Computing Environment (DCE) X/OPEN Directory Service (XDS), an application program interface (API) that DCE uses to access its directory service components. XDS provides facilities for adding, deleting, and looking up names and their attributes.

eXtended Data Service. XDS involves a system of data packets sent with the broadcast which can deliver: program rating information such as age-appropriateness, the current time, or local weather reports