My non-fiction books now carry the following disclaimer: Where we have traditionally been told we should use he and his, this book uses the singular they and their. For me, this usage is more compact, equalising and flexible than the alternative, clumsy he or she constructions. As the OED blog puts it:  People who want to be inclusive, or respectful of other people’s preferences, use singular they. And people who don’t want to be inclusive, or who don’t respect other people’s pronoun choices, use singular they as well. Even people who object to singular they as a grammatical error use it themselves when they’re not looking, a…