Most of us have heard the terms “half-staff” and “half-mast” when referring to our American flag. Are they interchangeable? Is one correct and the other not? A little research turns up some guidelines.
Both terms are used to describe a flag that is being flown halfway, or some other distance, down the flag pole. This tradition is used most often when a very notable person passes away (typically in the case of well-known politicians and leaders) or to commemorate a national or international tragedy.
When looking up “half-staff” in various dictionaries, most of the time you’ll be referred to the word “half-mast.” Merriam-Webster.com, for example links you to “half-mast,” where it gives this definition:
“a point some distance but not necessarily halfway down below the top of a mast or staff or the peak of a gaff”
However, the United States Flag Code consistently uses “half-staff” in all its writing about this aspect of flag flying. The website for the White House, in talking about this subject, also uses “half-staff” exclusively.
But in the end, the actual term you use is not as important as what a half-staff or half-mast flag represents. To be closest to what is most likely correct, however, you’re probably best to go with half-staff.