In part 3 we move beyond mechanics to look at grammar and usage (chapter 14) and selected stylistic and substantive issues (chapter 15). Here, as in mechanical matters, copyeditors are expected to correct or query whatever is incorrect in the manuscript, but the differences between correct and incorrect are sometimes harder to discern. On many points of grammar and usage, for example, even the experts offer conflicting advice. Thus copyeditors need to be able to distinguish between inviolable rules and personal stylistic preferences, with the goal of enforcing the former and respecting the author's choices in the latter. Chapter 14 surveys the gaffes most often committed by even good writers as well as the major battles in the grammar and usage wars.
The final challenge for copyeditors is to ensure that the text is clear and unambiguous at all levels—from individual words to sentences, paragraphs, sections, and chapters. Chapter 15 examines matters pertaining to organization, expository style, and the recent controversies over bias-free language. The last section of the chapter summarizes four legal topics (libel, privacy, obscenity, and copyright) of concern to copyeditors.