When the coronavirus threat grew earlier this year, Brian Stokle almost abandoned plans to debut his idea for a new San Francisco flag. With fear rising in the community, and lives at stake, who would have the time for such an esoteric and frivolous diversion?

But the bird on the logo kept staring back at him, suggesting the opposite may be true.

“I thought, ‘Wait a second. This might actually be the perfect time,’” Stokle said. “Maybe this could be a rallying cry for, ‘Hey, we’re going to make it through this. We’re going to be resilient, and the city will persevere, like the phoenix rising from the ashes.’”

Stokle’s symbolism-rich phoenix flag is now waving in more than a dozen San Francisco neighborhoods, after his first order of 31 banners arrived last week. With no marketing beyond his Twitter account and blog, he has orders for 42 more. And what started as a fun project for the 49-year-old Mission District resident is starting to feel like a movement.

The history of the San Francisco city flag is filled with rich symbolism and scorching ridicule. The city in 1900 adopted a basic phoenix logo, symbolizing its recovery from multiple fires and earthquakes in the 19th century. The phoenix flag was waving above City Hall when the 1906 earthquake and fire decimated the city once again.

But a disastrous 1930 redesign, some say, drained the personality from the flag, leaving what flag aficionados consider a cluttered mess. Negative attention surfaced over the years, then was amplified a hundredfold by “99% Invisible” podcaster Roman Mars, who called the San Francisco banner “sadly lacking,” making it the “what-not-to-do” centerpiece of a 2015 TED talk on flag design that has 4.5 million views.

That current San Francisco city flag has many problems, said Ted Kaye, secretary of the flag-centric North American Vexillological Association. The brown and black phoenix is too complicated, the gold border is too small and the flag is filled with lettering — the bane of flag connoisseurs.

“If I were improving the San Francisco flag, the first thing I would do is take off the words ‘San Francisco,’” Kaye said, during a phone call from his Portland home. “Because if you have to write the name of your place on your flag, then your symbolism has failed.”

Stokle said he was guided by Kaye’s booklet “Good Flag, Bad Flag,” which lists five principles of good flag design, including meaningful symbolism and a composition “so simple that a child can draw it from memory.”

Stokle’s earliest designs, incorporating rolling hills, fog and bridge symbolism, received a tepid response on social media and his Urban Life Signs blog.

“I kept doing designs,” Stokle said. “Some of them were hideous and some of them were all right. But it never went to, ‘Wow that’s really good. I can put that on my wall.’ ”

He was convinced by Twitter personality Burrito Justice to include the phoenix. Unable to draw one he liked, Stokle remembered an essay by history lover John Lumea about the 1900 flag. Stokle traced that old design, adding small tweaks to the eyes and head to make it “less fierce and mean.”

Stokle removed all the writing, shaded the top half gray to elicit fog, and the bottom half gold to represent the economic booms and busts of the region. The phoenix itself is crimson, Stokle said, to symbolize “our passionate hearts, and also the struggles and lost lives we’ve had over the years and decades.”

Seeing that he’d get a discount with 12, Stokle asked if anyone else wanted a flag. He ended up with 25 people ordering 31 flags. Those flags were shared on social media, leading to more orders. Now Stokle is selling them for $98 on a website, www.sffoggoldflag.com.

His flags are currently flying or adorning windows in districts including the Mission, Noe Valley, Nob Hill, the Bayview, Excelsior and Outer Richmond.

Sarah Rogers was in the first round of flag sales, buying one for her Bernal Heights home. She watched Stokle’s flag drive start as a quirky project, and become something San Franciscans can potentially rally around as they shelter in place.

“I’m not surprised to hear that he’s getting more and more interest in the flags,” said Rogers, who plans to install a pole for the flag. “It seems like a moment where people are looking for something to be proud of.”

Kaye said Stokle’s flag “‘is certainly an improvement over the current city flag.” Kaye likes the historic touches and the simplifications, while recommending an even more uncomplicated and stylized main logo.

“Interestingly, the city with the best phoenix on its flag is the city of Phoenix,” Kaye said.

Stokle is open to the criticism, and the possibility that his banner will never become a permanent San Francisco flag. But he said he hopes the interest is a clear sign to city leaders that a new flag would be a strong symbol of strength and rebirth, at a time when the city needs it again — and with so much hard work to come, a logo to rally around would be anything but frivolous.

“I think we just need a better flag for the city that we can all be proud of and would fly more often than we currently do,” Stokle said, “whether it’s my design or not.”

Peter Hartlaub is The San Francisco Chronicle’s pop culture critic. Email: phartlaub@sfchronicle.com Twitter: @PeterHartlaub