I just finished a master proofread, and boy, was it a doozy.

The master proofreader reads proof against copy, line for line, word for word, character for character. It requires intense focus. This is exhausting.

Don’t drive yourself crazy looking for the typo, OK?

In a master proofread, errors fall into two categories: printer’s errors and editor’s alterations. Both are flagged and corrected in the margin with conventional proofreader’s marks. If the compositor didn’t follow the manuscript precisely, the proofreader marks the correction “pe” (printer’s error). When the proofreader catches something that the author, editor, and copyeditor missed, she marks the correction “ea” (editor’s alteration) or something similar.

When authors make changes in proof, they’re called, big surprise, author’s alterations and marked “aa.”

The distinction is made between printer’s errors and editor’s or author’s alterations because print shops correct their own errors for free. When authors or editors make…