Nov. 11 is Veterans Day, one of six days a year that all USPS facilities must fly the POW-MIA flag.

Because Veterans Day is a designated Postal Service holiday, the POW-MIA flag should be raised Nov. 10.

The flag and its display honor the sacrifices made by members of the armed forces held as prisoners of war or missing in action.

The POW-MIA flag must fly below the U.S. flag.

See: USPS: Regulations for Proper Flag Display

Source: Veterans Day reminder | USPS News Link