I've never heard of one. Please tell us what the "unwritten rule" entails.
Well, maybe it's not a universal unwritten rule. A lot of times I look at things and think whether or not I would do them.
Personally, I would think it wouldn't be the kindest thing in the world to order 14 meals at the drive thru because I frequently think of the people around me.
If you have absolutely no concern for the folks behind you, by all means, go to the drive thru and order one of everything, all prepared in a special way.
I don't subscribe to the belief that because you
can do something, that you
should do something.
I can drive in the left lane doing 55, but I don't, I can walk into the paint department at Home Depot and take all the green Mickey Head paint color samples, but I don't.
If I were ordering meals and drinks for over a dozen people from MacDonalds, I'd probably carry a box in the store, put all the drinks in, put the bagged meals on top of them, and carry a box out to the car. I can't imagine sitting in my car having a drive thru attendant hand me 14 separate drinks, I'm not sure what I would physically do with those, only to be followed by 14 bags of food.
What I'm picturing though, is someone who hadn't thought about that either, while I am sitting right behind them.
One thing I can be sure of though, they didn't give me a moments thought.