Manuscript Preparation, Copyediting, and Proofreading
Q. In a jointly authored book in which each coauthor has written his own separate preface, can both prefaces be under one header, “Preface,” with each one signed? Or do I have to call one of them a preface and one something else, like a prologue? The trouble with the latter option is that they both are truly prefaces and serve exactly the same function.
A. It’s fine to call them both prefaces. Although prefaces are often signed at the end, in this case it might be better to put the byline at the top, right after “Preface.” In the table of contents, include both “Preface, by Author A” and “Preface, by Author B.”