When the American flag cannot be lowered to a half-staff to indicate a day of mourning, a black bow displayed above a US Flag can be used
Use with a flag or display alone.
Days on Which the US Flag Should be Displayed in Mourning by Order of Congress:
Peace Officer's Memorial Day- May 15
Memorial Day- The last Monday in May- only until noon
Korean War Veteran's Day- July 27
Patriot's Day- September 11
Pearl Harbor Rememberence Day- December 7