Extended Data Services (now XDS, previously EDS), is an American standard classified under Electronic Industries Alliance standard EIA-608[1] for the delivery of any ancillary data (metadata) to be sent with an analog television program, or any other NTSC video signal.
The CBS Television Network uses a similar method to transmit three separate internal messaging services to stations: one for programming departments, one for master control operations, and one for newsrooms.
Many standard definition receivers produced by Dish Network encode XDS data into their output signal.
XDS uses the same line in the vertical blanking interval as closed captioning (NTSC line 21), and shares the available second video field bandwidth with the closed captioning channels CC3 and CC4, and with the text channels TXT3 and TXT4.
XDS information is used by TV commercial detection software to skip advertisements.