Most people want a notification when something is said on a channel they have joined, particularly if they have been addressed directly. There is a global minor mode that will do this kind of tracking for you. All you need to do is switch it on using M-x rcirc-track-minor-mode. To make this permanent, add the following to your init file:
When other people say things in buffers that are currently buried (no window is showing them), the mode line will now show you the abbreviated channel or nick name. Use C-c C-<SPC> to switch to these buffers.
If you prefer not to load
rcirc immediately, you can delay the
activation of this mode:
(add-hook 'rcirc-mode-hook (lambda () (rcirc-track-minor-mode 1)))
If you've joined a very active support channel, tracking activity is no longer useful. The channel will be always active. Switching to active channels using C-c C-<SPC> no longer works as expected.
The solution is to mark this channel as a low priority channel. Use C-c C-l to make the current channel a low-priority channel. Low priority channels have the modeline indicator “LowPri”. C-c C-<SPC> will not switch to low priority channels unless you use the C-u prefix.
If you prefer a channel to never show up in the modeline, then you have to ignore it. Use C-c <TAB> to ignore the current channel.