modify RSS text in 3.01

the RSS entries for my standard-issue 3.01 blog all begin with a fairly long chunk of text, something like “Complex confusion has posted a new entry: ” which is fairly annoying when that gets reposted to my FB account. So I want to edit it.

I expected this to still be in a theme template, but apparently this is now in a function. Should I be overriding this, then, and can someone point me to some documentation? I believe everything I’m finding is far out of date.