Half-staff is defined as half the distance from the top of a flagpole to the bottom. If flying a single flag, the center point of the US flag should be aligned with the center point of the pole. If more than one flag is displayed on a pole, they all should be lowered to half-staff. Measure the length from the top of the first flag to the bottom of the last. Align the center point of the flag group with the center point of the pole. When a flag is flown at half-staff, it should be raised to the peak for an instant and then lowered to the half-staff position. When retiring the flag at the end of the day, this procedure should be repeated. If your flag is on an outrigger flagpole or mounted on a wall and cannot be flown at half-staff, it is appropriate to tie a black mourning ribbon above the flag.