You got me curious:
The U.S. Flag Code says, “The flag, when it is in such condition that it is no longer a fitting emblem for display, should be destroyed in a dignified way, preferably by burning.” When an American flag is worn beyond repair, it should be retired in a respectful manner.
And even more interesting, and from a reputable source:
https://www.google.com/url?sa=t&sour...=1618388883972