An expert in spelling, grammar, punctuation, word usage and style who gives writing its final review before production.

This expert is typically called a copy editor or a line editor. Their role is to ensure that the text is clear, concise, and error-free before it is published or distributed to the intended audience. They may also make suggestions for improving the overall flow and structure of the writing, as well as checking for consistency in formatting and referencing. Overall, the copy editor plays a crucial role in maintaining the professionalism and credibility of the written work.