PE (printer’s error--the customary term for what is generally a typesetter’s error), AA (author’s alteration), EA (editor’s alteration), and DA (designer’s alteration).Is there some sort of class distinction here? The tradespeople (unlike improvements, they can be considered “mere”) engage in errors; we professionals make alterations.
A recommendation, if I may. Let’s let our abbreviations acknowledge that even intelligent professionals, such as the authors we serve and even we our very good selves, commit errors. (The manual does acknowledge this, describing AAs and EAs in 2.131 and 2.132 as errors that need correction.) It would be an honest thing to do. It might even make the authors a little bit more shy about introducing changes in the proofs stage if they were asked to label them as errors. Not likely, but possible.