That'd just annoy the 99% of people that agree with McDonald's on what plain means. People at McDonald's are often in a hurry, and some would get really annoy

That'd just annoy the 99% of people that agree with McDonald's on what plain means. People at McDonald's are often in a hurry, and some would get really annoyed at stupid questions. Better to piss off the 1% than the 99%. If you're clarifying at this level, there are likely many other questions that you'd ask.