Hi @John I don´t agree with @Phil
John is the first name correct but Don is not the middle name , in fact the surname is Don Bosco altogheter .
There is no rule for names are surnames so it is hard to explain. In Spanish , Italian and others languages the word Don is used as honorific prefix follow by a first name.
Let´s say I am an older person or very powerfull one, people should call me Don Marcelo as a respect ... I like it : )