Anniversary. Birthday. Types of Water. Bread. Help. These are all signs that servers in a restaurant use to indicate to each other when they need to communicate or request help.
Of course, there are other formats used by high-end restaurants to keep track of service and customers they have gotten to know better. Of course, I'm not talking about the same when with my local taco shack. They know me but hardly anything sophisticated as a hand gesture is required to let the cook in the back know exactly what I know.
The Washington Post article called it "wordless routines". And if you consider it, there are other service-based businesses that could use wordless routines that involve some form of hand-based communication. And if not, they should.
In fact, I've done retail work where we have simple nods or gestures that allowed us to communicate with each other to save trips to the counter or having to walk across the store for something.
Whether it's a small store or a high-end restaurant, know what each server or salesperson is doing and being able to communicate it provides the appearance of seamless and efficient services being provided even if the customer isn't aware of it. And they're not suppose to.
Next time I go into a restaurant, I'll be watching out for these signals.