what does this symbol mean?
A black-and-white American flag with one blue stripe directly below the field of stars

Thin blue line flag

A black-and-white American flag with one blue stripe below the stars, flown to show support for police. No law or official body defines it, and people read it in different ways.

Easily confused with

How to read it

Police1, a law enforcement news site, describes the design: the stars stand for the citizens who stand for justice and order, the black for chaos and anarchy and, according to some, a memorial to officers who died in the line of duty, and the blue line for the police, borrowed from the idea of a line of defenders standing between peace and chaos. Thin Blue Line USA, a company Andrew Jacob founded in 2014 as a college student, claims to have put the blue line on a flag; Jacob told The Marshall Project he had seen the image on patches and stickers but not as a flag. Those who fly it have said it stands for solidarity and pride in a dangerous profession and is a tribute to fallen officers.

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These explain what each flag display means under the US Flag Code, federal law and military regulations, and who defines it. The Flag Code is a guide for civilians with no penalty attached; this isn’t legal advice.

Where the phrase comes from

The “thin red line” was a British battle formation of 1854, in the Crimean War. According to the lawyers James Clapp and Elizabeth Thornburg, quoted by The Marshall Project, the phrase was occasionally used of police and caught on in 1922, when New York police commissioner Richard Enright used it. In the 1950s Los Angeles police chief William H. Parker used it constantly in his speeches, and “The Thin Blue Line” was the title of a television show about his department.

How people read it

The Marshall Project sets the readings side by side. To Dallas police sergeant Stephen Bishopp it stands for respect and understanding for the families of officers killed in the line of duty. Michael White, a professor of criminology at Arizona State University, says: “It fosters this ‘us versus them’ mentality.” Some police agencies have taken it off their cars, stations and uniforms, Police1 says, and San Francisco’s police chief banned officers from wearing face masks with the flag, worried they would be seen as “divisive and disrespectful”. Some have asked whether it breaks the Flag Code, which says nothing should be placed on the flag; the American Legion had not taken an official position on it, a spokesman told The Marshall Project.

Look-alikes

The subdued flag on a soldier’s sleeve has no blue stripe; the Army’s is green and black.

More US flag variants

The same shape elsewhere

Sources

Researched, edited and approved by Rory Hansen before publishing. Last reviewed October 10, 2026. How we research

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