Proofreading Marks: A Complete Guide to What They Mean and How to Use Them

If you have ever received a printed document back from a professor, editor, or colleague covered in red ink and unfamiliar symbols, you already know how useful it is to understand proofreading marks. These standardized symbols are the shorthand professional proofreaders use to mark corrections on printed manuscripts. Knowing how to read them is a core skill for any writer who works with editors or submits documents for review. This guide covers what proofreading marks are, how they're organized, what the most common ones mean, and how the same corrections work in a modern digital workflow.

What Are Proofreading Marks?

Proofreading marks are standardized symbols and abbreviations that proofreaders use to indicate corrections on a printed document. Rather than writing out every instruction in full, proofreaders use a shared visual shorthand. It can be applied quickly and read clearly by anyone familiar with the system. Most proofreading marks appear in the margins of the document, usually written in red ink so they stand out from the original text.

A conventional approach places corrections that concern the first half of a sentence in the left-hand margin, and corrections that concern the second half in the right-hand margin. Not all proofreaders follow this practice strictly. It's a widely recognized convention that makes a heavily marked document easier to read and act on.

Proofreading marks are mainly used in print-based editorial workflows, where a proofreader reviews a printed proof or manuscript before final publication. In digital workflows, the equivalent is tracked changes in Microsoft Word, where every correction is marked inline and visible to the author. Understanding both systems is useful for writers working with professional editors in any context. For a broader introduction to what proofreading involves and when it's the right service for your document, read our article on what proofreading is.

Where Proofreading Fits in the Editing Process

Before diving into specific proofreading marks, it helps to understand where proofreading fits in the editorial process. Proofreading is the final stage of editing, applied to a document after all earlier editing revisions are done. It focuses on surface errors that survived earlier stages, including mistakes in grammar, punctuation, spelling, word usage, and formatting.

Proofreading isn't the same as copy editing or developmental editing. It doesn't address structural problems, argument clarity, or major language issues. It assumes the document is already well-written and well-edited, and gives the last quality check before the document is published or submitted. For more on how the stages relate, read our explainer on the difference between proofreading and editing.

Proofreading Marks Chart: Quick Reference

This chart summarizes the most common proofreading marks in all three categories, what each one means, and where you'll see it used. The detailed explanations follow below.

Common Proofreading Marks: A Complete Reference

Proofreading marks are typically organized into three main categories: punctuation marks, operational marks, and typography marks. Here's a complete reference for the most common marks in each category.

Punctuation Marks

Punctuation proofreading marks show that a specific punctuation mark needs to be inserted at a particular point in the text. Most use a caret symbol placed within the text to show exactly where the punctuation should go, with the matching symbol written in the margin.

Common punctuation proofreading marks include:

• Insert apostrophe. A caret with an apostrophe in the margin shows that an apostrophe is missing and should be inserted at the marked point. Commonly used for possessives and contractions.
• Insert comma. A caret with a comma in the margin. One of the most frequently used punctuation marks, since commas are among the most commonly omitted punctuation in unedited writing.
• Insert period. A circled dot in the margin shows that a period is missing at the end of a sentence.
• Insert question mark. A caret with a question mark in the margin, used where a direct question is missing its terminal punctuation.
• Insert exclamation point. A caret with an exclamation point in the margin, used sparingly in professional and academic documents.
• Insert colon. A caret with a colon in the margin, showing a colon is needed to introduce a list or elaboration.
• Insert semicolon. A caret with a semicolon in the margin, used where two independent clauses should be joined by a semicolon rather than separated by a period or joined by a comma.
• Insert hyphen. A caret with an equals sign (=) in the margin, the traditional symbol for a hyphen in proofreading notation.
• Insert em dash. Shown by a specific symbol in the margin, distinct from the hyphen mark. Em dashes set off parenthetical information or signal a strong break in a sentence.
• Insert en dash. Shown by a specific symbol in the margin, used mainly in number ranges such as page ranges and date ranges.
• Insert quotation marks. A caret with quotation marks in the margin, used where direct speech or the title of a short work is missing its enclosing marks.

Operational Marks

Operational proofreading marks show structural changes to the text itself, such as deletions, insertions, transpositions, and spacing corrections. These are among the most commonly used marks, and the ones most important to understand when you receive a marked manuscript.

• Delete. Shown by a strikethrough or a deletion symbol (resembling a looped d) through the word or words to be removed. The marked text should be removed entirely. This is one of the most self-explanatory proofreading marks.
• Delete and close up. A deletion symbol combined with a curved bracket that closes the gap, showing that a letter should be removed and the remaining letters closed up. Used when a letter has been accidentally doubled. For example, if "harass" has been spelled "harrass," the delete and close-up mark removes the extra r and closes the letters together.
• Insert. A caret placed within the text at the exact point of insertion, with the word or words to be inserted written in the margin. Used when a word or phrase has been accidentally omitted.
• Transpose. Shown by a curved line connecting two elements, or the abbreviation "tr" in the margin. This mark means the order of the marked words or letters should be reversed.
• Close up space. A curved bracket connecting two elements shows that an unwanted space should be removed.
• Insert space. A hash mark (#) in the margin shows that a space should be added between two words or elements that have run together.
• New paragraph. The paragraph symbol (¶) shows that the text at the marked point should begin a new paragraph. One of the most self-explanatory and frequently used operational marks.
• Run in. Shows that a paragraph break should be removed and the text should continue in the same paragraph as the preceding text.
• Stet. Written in the margin alongside a dotted line under the marked text, "stet" is the Latin word for "let it stand." It shows that a previously marked correction should be ignored and the original text kept as written.

Typography Marks and Proofreading Abbreviations

Typography proofreading marks show changes to the formatting, case, or style of the text. Proofreaders also use standardized abbreviations alongside these marks to communicate specific typographic instructions concisely.

• Capitalize (caps / uc). Three lines under a letter, or the abbreviation "caps" or "uc" (uppercase) in the margin, shows that the marked letter should be capitalized.
• Lowercase (lc). A diagonal line through a capital letter, or the abbreviation "lc" in the margin, shows that the marked letter should be changed to lowercase.
• Italicize (ital). A single underline under the text, or the abbreviation "ital" in the margin, shows that the marked text should be set in italics.
• Bold (bf). A wavy underline under the text, or the abbreviation "bf" (bold face) in the margin, shows that the marked text should be set in bold.
• Remove bold or italics (rom). A circled word, or the abbreviation "rom" (roman) in the margin, shows that bold or italic formatting should be removed and the text set in regular roman type.
• Small caps (sc). A double underline under text, or the abbreviation "sc" in the margin, shows that the marked text should be set in small capitals.
• Wrong font (wf). A circle around the text, or the abbreviation "wf" in the margin, shows that the marked text appears in the wrong typeface and should be corrected.
• Spell out (sp). A circle around an abbreviation, or the abbreviation "sp" in the margin, shows that the marked text should be spelled out in full rather than abbreviated.

How Proofreading Marks Are Used in Practice

In a typical print proofreading workflow, the proofreader reads through a printed proof carefully, marking errors directly on the page. The proofreader places the correction symbol within the text at the exact point of the error, and writes the matching instruction in the margin. This dual system, one mark in the text and one in the margin, makes both the location and the nature of each correction clear.

For documents going through multiple rounds of proofreading, a proofreader may mark a correction in one round and then decide during a later review that the original text is fine. In that case, they use the stet mark alongside the earlier correction to show it should be disregarded and the text left as it was.

In digital editorial workflows, tracked changes in Microsoft Word serve the same function as proofreading marks on a printed page. Every correction is marked inline, the original text is preserved in strikethrough, and the author can accept or reject each change individually before finalizing. At Editor World, every edited document is returned with tracked changes, so you can review every correction before the document is final.

Why Understanding Proofreading Marks Matters

Even in an era of digital editing, understanding proofreading marks remains a valuable skill for writers and academics who receive printed feedback, work with traditional publishers, or review proofs before publication. Knowing what a stet means, understanding the difference between delete and delete-and-close-up, and recognizing typography marks for capitalization and italics lets you respond accurately to editorial feedback and apply corrections precisely.

More broadly, knowing proofreading marks deepens your understanding of the proofreading process itself: what proofreaders look for, how they communicate their findings, and what standard a professionally proofread document is expected to meet. That understanding helps you work more effectively with professional editors at every stage of writing and revision.

From Red Ink to Track Changes: Getting Your Document Proofread

Most professional proofreading now happens digitally, so you don't need to decode margin symbols to get expert help. When you submit a document to Editor World's professional proofreading services, your proofreader marks every correction with Track Changes in Microsoft Word. You see exactly what changed and why, and you accept or reject each edit yourself. It's the same precision as a red-ink proof, with none of the guesswork about what a symbol means.

A few things set Editor World apart from services that assign you an unnamed editor. You choose your own proofreader from verified profiles, matching their subject background to your document. Every proofreader is a native English speaker from the USA, UK, or Canada who has passed a rigorous skills test. Every document is reviewed by a real person, with no AI at any stage. Turnaround options start at 2-hour same-day editing, and pricing is clear from an instant quote before you commit. You can try the quality first with a free sample edit of your first 300 words.

Frequently Asked Questions

More from Editor World

For more on proofreading and the editing process, see our guides to what proofreading is and the difference between proofreading and editing. When your document is ready for a final check, our professional proofreading services and academic editing services can help.

Content reviewed by the Editor World editorial team. Editor World, founded in 2010 by Patti Fisher, PhD, graduate of The Ohio State University, provides professional human-only editing and proofreading for students, academics, businesses, and authors worldwide. BBB A+ accredited since 2010 with 5.0/5 Google Reviews and 5.0/5 Facebook Reviews. More than 140 million words edited for over 8,000 clients in 65+ countries. Multiple Gold and Bronze Stevie Award winner. Native English editors from the United States, the United Kingdom, and Canada. Less than 5% acceptance rate. Recommended by the Boston University Economics Department, University of San Diego, University of Michigan, UCLA, University of Missouri, and more. No AI tools are used at any stage. Page last reviewed July 2026.