My students have an assignment to summarize a chapter from an introductory textbook in their field, and I recommend that they vet the chapter with me before proceeding. One student brought me Civil Law and Litigation for Paralegals by Neal R. Bevans (McGraw-Hill, 2008), which had the following blurb in the front matter:
"The author has adopted the convention of employing 'he or she' whenever the text demands the use of the third-person singular voice." (p. ix)
I would guess that this was included by an editor and not the author, but it's hard to know. Whoever put it there likely meant something like: 'wherever an epicene third-person singular pronoun is called for'. And presumably, he or she is meant to include the various shapes those words take (i.e., him or her, his or her(s), himself or herself), and who knows what in the world is meant by voice. Clearly, it's not the active/passive distinction they had in mind.
What they're really saying is, when the gender of the referent is unclear, the author avoids the lone masculine pronoun as well as what has come to be called singular they.
But for fun, let's take this literally (or at least as literally as meaning allows). If the convention were actually followed, the introduction would change from this:
"Before we can discuss the many fascinating aspects of civil litigation, we must begin with an examination of the American judicial system. The purpose of this chapter is to introduce you to the important distinctions between civil law and other types of law, as well the sources of judicial authority. Finally, we will examine the major features of both the federal and state court systems. As you will see, there any many different sources of legal authority, and each plays an important role in the overall pattern of civil litigation."To this:
"Before we can discuss the many fascinating aspects of he or she, we must begin with he or she of he or she. He or she of he or she is to introduce you to the important distinctions between he or she and other types of he or she, as well the sources of he or she. Finally, we will examine the major features of both the federal and he or she he or she systems. As you will see, there any many different sources of he or she, and he or she plays he or she in he or she of he or she. "