It did? My wife keeps insisting I just leave it out, and I can't do that. Don't tell me she's right.
Technically she's right. The theory is that it's far better to fly the flag than not, and people shouldn't let lack of a light cause them to not fly it or to retire it.
The Flag Code was created by Teddy Roosevelt, and contains the basic rules for display and respect of the Flag. That includes the condition that the flag be retired in inclement weather, but allows that it may be displayed by private citizens at night, if properly lighted.
The Flag Code hasn't been altered in that respect; it's also not legally binding, in that there is no provision for enforcement. Violation of the flag code does not carry a penalty.
There is no binding requirement to light, or not light the flag at night. The Flag Code still carries that requirement, but again, it's not binding or a requirement to the private citizen. Also worth noting is that the same provision in the Flag Code that applies to lighting the flag requires retiring during inclement weather, except for all-weather flags, such as modern flags made of nylon.
Another popular misconception has been a requirement to burn the flag if it touches the ground. This is not, and never was the case.
The flag code stipulates that flags may never be worn. You may notice that SWA, among other companies, authorizes it's pilots to wear flag ties; these ties are classified as the wearing of the flag, and constitute violations of the Flag Code.
Another interesting tidbit of respect and decorum given the flag was that of the salute; originally it was a military salute, as designed by the writer of the Pledge. However, it was changed to hand over the heart, and upon completion of the Pledge of Allegiance, the hand was extended toward the flag, palm down. Entering WWII, that token of respect was determined to be too similar in appearance to the Nazi salute, and was dropped back to hand over the heart.
More than you ever wanted to know about display of the Flag:
http://www.ushistory.org/betsy/flagcode.htm