You can use it in whatever channel you want, you click on link all and it copies the links of all the item into your chat bar.
So if you want to tell your gruop what is on the corpse type
/g then click the link all button
They'll be able to click on the name and see the info for it.
You can also link just one item by right clicking on the item, holding the button down while moving your mouse to the picture of the item in the info window, and then left clicking (or right clicking??) on the item in the INFO WINDOW. Very important you don't accidently click on the actual item or else you'll loot it, and if it's no drop that could get someone mad.