Well, it is a law in the sense that it is encoded in something called the U.S. Flag Code. However, if you look at the text itself, it basically says that it is not a statute. That’s pretty good evidence that it is not “the law.”
“Law” can have many meanings, but, in general, in the United States, there are three kinds of law – statutes (legislation adopted by a legislature and signed by an executive), black-letter law (law made by judges in deciding cases), and regulatory law (regulations written by regulatory agencies under the authority of statutory law). All three kinds of law can be enforced against an individual in court, either in a civil or criminal action.
It seems to me that the language of the U.S. Flag Code implies that it can’t be enforced against an individual in court. There is good reason for this, of course. If the Flag Code contained provisions granting the state the power to enforce it, then it would be immediately found to be unconstitutional. All this, to me, is strong evidence that it is not, in fact, “the law,” but, instead a set of guidelines.
As for our “responsibilities” with respect to the flag – speak for yourself. I own several flags and I display them more or less in line with the Flag Code, but I do so because I want to do so, not do so because I think it is my “responsibility” to do so.
A flag is a symbol that can have quite a large number of meanings ascribed to it – the people of the country, the government of a country, particular officials or agencies, the armed forces, the policy of the government, the nation in general, the “spirit” of the nation, the history of the nation, actions abroad by citizens (such as large businesses), etc.
Treatment of It is up to an individual to decide for himself or herself what meaning to ascribe to it and the appropriate treatment to follow. The attitude towards the flag and its due treatment might change from day-to-day for any one person.
Furthermore, it is entirely possible for an individual to be in complete accordance with the Flag Code’s authors with regard to the attitude and intent towards the flag, but to disagree with their ideas on what should be considered proper or respectful handling or display.
As Americans, we get to make our own minds up about such things; we aren’t obligated to defer to the expertise of some self-appointed authority on expression, be it Congress or whoever else. (Congress isn’t self-appointed for its constitutional duties, but, when it comes to a matter regarding individual expression, it’s definitely exceeding its proper authority, and the Supreme Court has let it know so on a number of occasions.)
Whatever your own feelings about the importance of the flag, its meaning, and its due treatment, what I said remains true – there can be no absolute legal authority that can dictate to any individual how he or she must display, handle, or treat a flag.