Except perhaps on Saturday mornings, and even then you probably shouldn’t

Given the origins of “au lait”—literally French for “with milk”—it seems logical to assume this simple drink, a hot cup of coffee with hot milk, would be a mainstay in Paris. Au contraire.

Shortly after we arrived in Paris, a friend in New York whose wife is from France emailed his advice on a range of local etiquette. When it came to coffee, he wrote, “only on a Saturday morning from time to time can you order a café au lait.” His explanation: many residents tend to make coffee in this style in their own homes, especially on weekends, so they wouldn’t go to a cafe to do the same. A few days later, an American who lived in Paris with her family for several years said very much the same, except stricter: never order a café au lait.

The consequences of such a misorder are relatively minor: you’ll likely get a mediocre coffee that costs more than you’d expect. (The taste and price of which may be improved by the romance of sipping it in Paris.) If you’re worried your servers will peg you as a tourist, let’s be honest: they already can. But if you go ahead and order a cafe au lait, they’ll know you’re not even trying.

You certainly won’t be at a loss for great coffee throughout Paris (for instance, near Montmartre), whether you choose to sit unhurriedly with a perfunctory cup as your anchor at a corner cafe or savor the craft of the growing number of contemporary coffee shops featuring specialty roasts and baristas who approach their work as an artform. But as ubiquitous and straightforward as a coffee may seem to most daily drinkers, whenever traveling it’s worth a chat with local friends or a quick search to understand local customs and glean unexpected tips.

And if you’re still craving milk in your coffee while in Paris, I’ve heard that a cappuccino is your safest order, even with its Italian roots.