In Australian or New Zealand English, is the term "Sausage sizzle" only used for charity events, as opposed to a BBQ that you're having with friends?
Wikipedia has an entry on sausage sizzle, but I don't trust it, as it describes a food item, as opposed to the event, as being the sausage sizzle, which I've never heard before. (Perhaps they're thinking of sausage sandwich - ironically, that page seems to have a more accurate definition of a sausage sizzle!)