A channel is the part of a server where users may talk in a many-to-many manner. ChanServ usually takes care of channel management, but there might be a few servers without it. Channels can have modes, and there is a URI Parameter for both the widget and the main client.
As a URI Parameter, this is a necessary parameter for widgets. The most basic form is:
The '%23' is the URL Escape code for a '#'. If multiple channels wish to be used, add a comma at the end of the channel name, and place another one. This form looks like:
In the widget, this parameter tells the widget which channels to join after connecting to the server. In the main client, this parameter fills out the server connection form for easier server connections (but only if you have &server=any.blah.ext as well).
Replace "&" with "?" for the the first parameter.