Copper Multicast - What is it?

[#1]

Hi,
In the last week we've had a new Cabinet installed in Salisbury Cabinet 54 and on http://dslchecker.bt.com/ this evening it says 'Other Offerings Copper Multicast' but what does this mean?
Thanks

[#2]

Basically it is TV channels streamed down the phone line using your internet connection.
The old BT Vision and Tiscalli TV used to stream down copper wire, now it's mainly YouView.