It is the universal custom to display the flag only from sunrise to sunset on buildings and on flag staffs in the open.  However, when a patriotic effect is desired, the flag may be displayed twenty four hours a day if properly illuminated during the hours of darkness.

The  flag should be hoisted briskly and lowered ceremoniously.

The flag should not be displayed on days when the weather is inclement, except when an "all-weather" flag is displayed.

The flag should be displayed daily, on or near the main administration building of every public institution ... in or near every polling place on election days .... during school days in or near every schoolhouse.

No other flag or pennant should be place above or, if on the same level, to the right of the flag of the United States of America, except during church services conducted by naval chaplains at sea ... for personnel of the Navy ... when the church pennant may be flown above the flag.

No person shall display the flag of the United Nations or any other national or international flag equal, above, or in a position of superior prominence or honor to, or in place of the flag of the United States at any place within  the the United States or any territory or possession thereof: Provided, that nothing in this section shall make unlawful - the continuance of the practice heretofore followed of displaying the flag of the United Nations in a position of superior prominence or honor, with that of the flag of the United States at the headquarters of the United Nations.

Displaying With Other Flags

The flag of the United States of America, when displayed with another flag against a wall from crossed staffs, should be on the right, the flag's own right, and its staff should be in front of the staff of the other flag.

The flag of the United States of America should be at the center and at the highest point of the group when a number of flags of states or localities or pennants of societies are grouped and displayed from staffs.

When flags of States, cities, or localities, or pennants of societies are flown on the same halyard (rope) with the flag of the United States, the latter should always be at the peak.  When the flags are flown from adjacent staffs, the flag of the United States should always be hoisted first and lowered last.  No such flag or pennant may be placed above the flag of the flag of the United States or to the United States flag's right.

When flags of two or more nations are displayed, they are to be flown from separate staffs of the same height.  The flags should be of approximately equal size.  International usage forbids the display of the flag of one nation above that of another nation in time of peace.
 
 

When the flag of the United States is displayed from a staff projecting horizontally or at an angle from the window sill, balcony, or front of a building, the union of the flag (stars) should be placed at the peak of the staff unless the flag is at half staff.  When the flag is suspended over a sidewalk from a rope extending from a house to a pole at the edge of the sidewalk, the flag should be hoisted out, union (stars) first, from the building.

Wall Display Without Staff

When displayed either horizontally or vertically against a wall, the union should be uppermost and to the flag's own right, that is, to the observer's left.  When displayed in a window, the flag should be displayed in the same way with the union or blue field to the left of the observer in the street.

When the flag is displayed over the middle of the street, it should be suspended vertically with the union to the North in an East and West street, or to the East in a North and South street.

Flag No-Nos

The flag should never be displayed with the union down, except as a signal of dire distress in instances of extreme danger to life or property.

The flag should never touch anything beneath it, such as the ground, the floor, water or merchandise.

The flag should never be fastened, displayed, used, or stored in such a manner as to permit it to be easily torn, soiled or damaged in any way.

The flag should never be used as a covering for a ceiling.

The flag should never have placed upon it, nor on any part of it, nor attached to it, any mark, insignia, letter, word, figure, design, picture, or drawing of any nature.

The flag should never be used as a receptacle for receiving, holding, carrying, or delivering anything.

Some of the information on these pages was provided by the Annin Company and the National Flag Foundation