In the early weeks of the pandemic, when we had to make our own masks or go without, a friend sewed pleats into a soothing blue-and-white rectangle of cotton with ties at the corners and gave them away. I still wear mine, even though many New Yorkers have moved on to the style with elastics that loop behind the ears.

Whenever I mask up, I have to make two shoelace knots behind my head, and I am proud to say that after almost five months, I no longer need to say, “the bunny rabbit comes out of the hole and goes around the tree” each time I leave the house. But I still fumble with my mask like a kid who is about to come in last in a game at the world’s most boring birthday party.

So while the bartender of a Brooklyn restaurant stood next to my sidewalk table last week, waiting for me to tell him what I wanted to drink, I struggled with the laces at the back of my scalp. A minute stretched into two or three. I don’t get faster at tying knots behind my head when I’m being watched.

“I thought the rule was ‘Sit Down, Masks Down; Stand Up, Masks Up,’” he said. “Isn’t that what we’re doing?”

Actually, I don’t know what we’re doing. As far as I can tell, nobody else is quite sure, either. Walk past almost any open business in the city and you’ll see signs informing you that you need to wear a face covering to come inside. Almost everybody complies.

But outdoor restaurant dining is where New York’s more-or-less general agreement about masks unravels into confusion.

The state Department of Health says that restaurants “should encourage, but not require customers to wear face coverings when not eating and/or drinking.” The website of the city’s Department of Health and Mental Hygiene has posted similar guidance for diners. According to the department, “face coverings are not required when diners are seated, but wearing a face covering as much as possible once at the table is the best way to reduce the risk of Covid-19 transmission for restaurant workers and dining companions.”

My outdoor restaurant meals since late June suggest that this advice has reached very few diners. I’ve seen a smattering of people who keep their faces covered until the first drink or plate of food arrives, then cover up again when they’ve had enough. Should the meal be served in actual courses, a rarity these days, these people bring the masks out again between the appetizer and the main course.

Far more New Yorkers choose to set their faces free the minute they sit down, if not before, stowing their masks in their pockets, around their necks like surgeons or in that chin-strap position that makes them look as if they’ve just been to see a medieval dentist. They stay that way, chatting and gossiping and sucking on metal straws and putting away lunch or dinner until the check has been paid. Usually, but not always, they slip their masks on as they leave.

The appeal of this approach is clear. Masking and unmasking repeatedly can be awkward, particularly when you’ve got a fork in one hand and a knife in the other. Besides, conversing in a mask is a bit like swimming in a jumpsuit. It can be done, but it takes more effort. If you have reason to believe everybody at your table is healthy, the temptation to talk the way you used to do, employing the full range of lower facial contortions from the closelipped smirk of an inside joke to the slack-jawed gape of astonishment, can be very strong.

Gov. Andrew M. Cuomo has chided restaurants that flagrantly disregard social distancing and masking rules. A state task force has cited hundreds of establishments for violations, and suspended the liquor licenses of some, frequently when unmasked customers were standing in tight clusters.

Much less has been made of the official guidance on wearing masks while seated. It’s rare to find a restaurant that enforces, or even mentions, the advice, despite the preponderance of signs instructing diners how to pay through Venmo or bring up a menu by scanning a QR code. The downtown restaurant Frenchette is unusual for having a note on its website asking diners to wear masks “when any staff is table-side.” I went the other night. The only people in masks were the ones who worked there.

Another restaurant downtown, King, asks customers in person to wear masks while talking to servers. “We get the occasional rude response,” Annie Shi, one of the owners, wrote recently on Resy, “but most guests appreciate that we are taking care of our staff, and as result, of them.”

Other restaurant owners may not be aware of the health department’s advice. Or they may have heard about mask-hating thugs who’ve threatened mask-wearing workers in other parts of the country. Most likely, though, restaurateurs are simply afraid to do anything that might keep customers away. In a summer when a thunderstorm can wipe out a night’s revenue, every table counts.

The writer and editor Corby Kummer, whose Food and Society Program of the Aspen Institute collaborated with the James Beard Foundation to prepare detailed Covid-19 safety protocols for restaurants, is now working on what he calls a “code of conduct” for diners. The rules, which could be made a condition of placing a reservation, would be simple and few: Whether sitting indoors or out, don’t crowd the host stand or the restrooms, wear a mask when away from the table and comply with polite requests from the staff. Even these modest requests can make some owners nervous.

If every restaurant simply repeated the city’s advice, posting it on signs and menus, the message might stick. And it might help make up for the lapses in physical distancing that are almost inevitable in restaurant dining. Just because all the tables are spaced six feet apart does not mean that all the seats will be. Some groups of people tend to sprawl out and take more space. While eating out, I’ve found myself closer to other diners than I would have liked.

I’ve also been guilty of getting too close to pedestrians, just by sitting at an outdoor table. Restaurants are supposed to leave a clear, eight-foot-wide corridor on the sidewalk. In practice, though, I’ve found myself less than two feet away from the faces of people out who are out walking the dog, strolling the toddler or simply circling the block trying to remember what it felt like to come home from work.

That’s one reason I wear a mask when my mouth isn’t full. The main one, though, is that when my face isn’t covered and I have to talk to a bartender, busser, server or manager in a mask, I feel like a heel. Maybe those people came back to work because they want to help me enjoy a night away from home. Or maybe they were afraid that if they said no to working this week, they might not be asked again next week.

But however those employees ended up on the sidewalk, helping me get over the lingering effects of house arrest, they’re taking a risk on my behalf. Putting on a mask is a simple way to show some respect for them, even if it means reaching awkwardly behind my ears.