In 1942 Congress passed a joint resolution summarizing the customs and rules for display of the U.S. flag. The basic rules are:
When flown from a pole the fly end of the flag should be able to fly freely. Do not secure it to a frame.
Display the flag only during daylight in good weather. Take it down when it gets dark or if it starts to rain or snow. You may display it at night in good weather if it is lighted.
Do not let the flag touch the ground, water, buildings, or merchandise. Do not carry the flag in a parade by the edges (flat) or attached to a pole along the top.
The flag should not be draped on a car or podium. Instead use red, white, and blue bunting with the blue at the top.
If the flag is used to cover a casket the canton should be placed over the left shoulder. Remove the flag before lowering the casket into the grave.
When displayed on a wall, the flag's canton should be on the left as you view it.
Use in parades or processions and display with other flags can get complicated. See other resources on this page.
Do not use the flag for advertising a product and do not print or embroider the flag on anything designed for temporary use and discard.
When the flag is no longer fit for duty (threadbare, faded, torn, or dirty) it should be destroyed in a dignified manner (preferably by burning).