I’ve been working on a biography of Donald Coxeter, one of the most important geometers of the 20th century. I mean reading it, since the hard work of writing it was already done by someone else (Siobhan Roberts), and the even harder work of being an important geometer of the 20th century was done by another person entirely (Donald Coxeter). Mine is really the easiest part except for the people who aren’t reading it, who can do that anytime and from anywhere. Anyway, I’d run across some of his work in references to H M S Coxeter, and a careful examination of the first paragraph pointed out that “Donald” is not one of the leading names with an initial H, M, or S.
Anyway, Roberts explains that Donald’s parents wanted to call him Donald, and they did, but “the birth certificate recorded his first name officially as MacDonald, after his father’s father”. Fine and/or dandy. His mother added “Scott” to honor another relative, and a godparent suggested that he should have his father’s name of Harold, too, and that’s why he was Harold Scott MacDonald Coxeter.
And I just admire how very much that looks as if it explained the situation.