Howto set up specific filters

How do I set up a specific filter in BRO? For example, I want to filter
thinks like aim, irc, edonkey, bittorrent...etc.

Thanks,
David Caldwell

Sorry, I'm not sure what you mean by "filter" here. Are you refering
to a packet filter, i.e., a BPF expression? Do you want to include,
irc etc. traffic or filter it out?

Robin