The first time you get a manuscript back from a professional proofreader, the page can look like it was attacked: carets between words, loops through letters, cryptic abbreviations stacked in the margins. Those symbols are proofreading marks, a standardized shorthand that editors and proofreaders have used for generations to flag corrections on paper faster and more precisely than written comments ever could.
I have published several books and spent years around editors, ghostwriters, and publishing workflows, and my honest advice is this: do not be intimidated by a heavily marked page. Every one of those symbols is a specific, solvable instruction, and a proofreader who marks a lot is doing their job, not attacking yours. The skill you need is simply reading the code.
This guide explains what proofreading marks are, whether anyone still uses them in a track-changes world, how a marked-up page is laid out, and what the most common symbols and margin abbreviations mean, with examples of how each one is used.
What Are Proofreading Marks?
Proofreading marks, also called proofreaders' marks or proof correction marks, are a set of standardized symbols used to indicate errors and required changes on a physical or typeset page. Because a proofreader traditionally could not change the text itself, only annotate it, the marks evolved as a compact instruction language: one symbol tells the typesetter or author exactly what to fix and where.
The system covers everything a final check needs to catch: typos and misspellings, punctuation errors, deleted or repeated words, spacing problems, paragraph breaks, capitalization, and formatting instructions like italics or boldface. Style authorities publish reference charts of the standard set, and the proofreaders' marks chart from The Chicago Manual of Style is the one I would bookmark, since Chicago style governs most US book publishing.
One clarification that trips writers up: proofreading is the last stage of editing, the final error sweep before publication. It is not the stage where an editor questions your structure or rewrites your sentences. If your document still needs that deeper work, you want an editor first, and my guide on how to find and work with an editor explains how those roles differ and how to hire for each.
Are Proofreading Marks Still Used?
Less than they were, but more than you might expect. Most commercial proofreading now happens digitally in Google Docs or Microsoft Word, where suggested edits and tracked changes have replaced pencil marks for everyday business and web content. If you only ever write online copy, you may go years without seeing a caret in a margin.
Book publishing is the big exception. Page proofs, the typeset pages produced before a book prints, are still commonly reviewed as PDFs or physical printouts, and marks remain the fastest unambiguous way to annotate a typeset page without touching the underlying files. Traditional publishers, typesetters, and many veteran freelance proofreaders still work in this shorthand, which means authors who sign a publishing contract will likely meet it. If you are still drafting and proofs feel far away, my guide on how to write a novel covers the stages that come long before this one. Understanding the marks also has a quieter benefit: each symbol names a specific error category, so learning the system trains you to see your own drafts the way a proofreader does.
How a Marked-Up Page Works
Proofreading marks come in pairs: a small mark in the text shows where the change happens, and a corresponding mark in the margin says what the change is. On a traditional pass, corrections for the first half of the line go in the left margin and corrections for the second half go in the right margin, read in order. The marginal flag is what makes the system scannable; a typesetter can run down the margins and never miss a correction buried mid-page.
Hard-copy proofs are conventionally marked in red ink for visibility, with the proofreader's name and the date noted on the page. When a proofreader makes a correction and then changes their mind, they write stet, Latin for "let it stand," with dots under the original text, which tells everyone to ignore the crossed-out correction and keep the words as they were.
Common Proofreading Marks and What They Mean
Here are the marks you are most likely to meet on a marked-up manuscript, with what each instructs you to do.
Insertion and Deletion Marks
The caret, a small upward wedge placed between two words or letters, means insert here, with the missing text written above the line or in the margin. Its inverted twin is used for inserting apostrophes or quotation marks above the line. Deletion is marked with a line through the offending text plus a looped delete symbol, traditionally shortened to dele, in the margin. So in the sentence "the the deadline is is Friday," a proofreader would strike one "the" and one "is" with delete loops, and if a word is missing, "the deadline Friday," a caret between "deadline" and "Friday" with "is" written above fixes it.
Spacing and Paragraph Marks
The space mark, written as the hash-like symbol #, means insert a space, as in "thedeadline" needing one. Its opposite is the close-up mark, two curved lines bracketing a gap like a sideways parenthesis sandwich, which means remove the extra space in "dead line." The paragraph symbol tells you to start a new paragraph at that point, the standard fix for a wall of text carrying two separate thoughts, while "run in" or connecting lines instruct you to merge a paragraph break that should not exist. The transpose mark, a curved line weaving over one element and under the next with tr in the margin, means swap the order, turning "only I said that" into "I only said that."
Capitalization and Formatting Marks
Three short lines under a letter mean capitalize it, and a slash through a capital letter means make it lowercase. A single underline with ital circled in the margin means set the text in italics, the standard instruction for a book or journal title, and if you are unsure which titles take italics in the first place, my reference on whether you underline book titles settles it. A wavy underline with bf in the margin means set in boldface. Punctuation has its own small vocabulary: a circled dot marks an inserted period, and an em dash insertion is flagged with its own symbol where the proofreader wants that longer dash set.
Margin Abbreviations
Alongside the symbols, proofreaders use short abbreviations in the margins to name the problem:
sp: spelling error, or an instruction to spell out an abbreviated word in full
stet: let it stand, meaning ignore the marked correction and keep the original text
tr: transpose the marked letters or words
ital: set the underlined text in italics
bf: set the marked text in boldface
lc: make the marked letter lowercase
caps: set the marked text in capitals
wf: wrong font, where text is set in the wrong typeface or size
DICT: incorrect diction, the wrong word for the intended meaning
REP: unnecessary repetition to cut or reword
R-O: run-on sentence that needs splitting or repunctuating
AWK: awkward construction that reads badly and needs rearranging
The bracket symbols also appear as alignment instructions: an opening bracket means move the text left and a closing bracket means move it right, drawn tall enough to cover the lines affected.
Proofreading Marks in Digital Documents
Digital proofreading kept the logic of the mark system and swapped the pen for software. Track changes in Word and suggesting mode in Google Docs show deletions as strikethrough text, insertions in a contrasting color, and comments in the margin, which maps almost one to one onto the old text-mark-plus-margin-note structure. Where a paper proofreader wrote AWK, a digital one leaves a comment; where the paper margin said tr, the suggestion simply shows the words reordered.
My recommendation for working writers is to be fluent in both directions. Accept or reject tracked changes deliberately rather than in bulk, because each suggestion is a judgment you are entitled to overrule, and stet exists for a reason. And when a proofreader returns a marked PDF of your typeset pages, resist making the fixes directly in your manuscript file from memory; work through the marks one by one in order, checking each off, the same way a typesetter would. Skipped corrections are how errors survive into print, and they matter twice as much once your pages are laid out, since even small text changes can reflow a design. That is also why final-stage corrections and book formatting decisions belong in the same conversation.
A page covered in proofreading marks is not a verdict on your writing; it is the last quality gate between your draft and your readers, doing exactly what it should. Learn the twenty or so symbols above and a marked-up proof stops being intimidating and becomes what it always was: a fast, precise conversation between people who all want the same clean final page. And if you find you enjoy that final-gate work more than most writers do, proofreading is a genuine career path, and the market for freelance editing jobs is one place to see what it pays.
Proofreading marks are essential tools for ensuring accuracy and quality in written work, particularly during the final editing phase. Symbols such as the caret for insertions, "dele" for deletions, and abbreviations like "stet" help turn feedback into clear, actionable instructions. These marks are widely used in book publishing and remain effective for any task requiring precise corrections.
Modern tools like Word and Google Docs have adapted these marks into digital workflows, offering functions like tracked changes and comments. Reviewing each suggestion individually ensures edits are deliberate and meaningful. A heavily marked page is not a critique but a step toward perfection, ensuring your work is polished and prepared for readers. Learning these symbols or working effectively with proofreaders can elevate the final product and leave nothing to chance.
Related Resources
Frequently Asked Questions
Here are the most frequently asked questions about proofreading marks.
What are proofreading marks?
Proofreading marks are standardized symbols that editors and proofreaders use to flag corrections on a manuscript or typeset page. Each mark pairs an in-text symbol showing where the change goes with a margin note saying what the change is, covering spelling, punctuation, spacing, capitalization, and formatting.
Are proofreading marks still used today?
Yes, though mostly in book publishing. Everyday business and web content is now proofread digitally with tracked changes, but publishers, typesetters, and many veteran proofreaders still mark up page proofs on paper or PDF, where the symbols remain the fastest unambiguous annotation method.
What does stet mean in proofreading?
Stet is Latin for "let it stand." A proofreader writes it, usually with dots under the affected text, to cancel a correction they previously marked. It tells the author or typesetter to ignore the crossed-out change and keep the original wording.
What does the caret symbol mean?
The caret, a small upward wedge placed between words or letters, means insert here. The missing text is written directly above the line or in the margin. An inverted caret above the line marks insertions that sit high in the text, such as apostrophes and quotation marks.
What is the difference between proofreading and editing?
Editing improves the substance of a piece: structure, clarity, flow, and word choice. Proofreading is the final pass after editing and layout, catching surface errors like typos, punctuation mistakes, and formatting slips. Proofreading marks belong to that last stage, when the text itself is considered settled.
Do I have to accept every proofreading correction?
No. Marks are professional recommendations, and the author usually has the final say, especially on style choices rather than outright errors. Work through corrections one by one, accept the fixes, and consciously overrule the rest rather than accepting or rejecting everything in bulk.