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 language professional proofreaders use to communicate corrections and instructions on printed manuscripts, and knowing how to read them is an essential skill for any writer who works with editors or submits documents for review. This guide covers what proofreading marks are, how they are organized, what the most common ones mean, and how the proofreading process works.

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 that can be applied quickly and read clearly by anyone familiar with the system. Most proofreading marks appear in the margins of the document, typically written in red ink to distinguish them clearly from the original text.

A conventional approach to placing proofreading marks involves writing corrections that concern the first half of a sentence in the left-hand margin, and corrections that concern the second half of the sentence in the right-hand margin. Not all proofreaders follow this practice strictly, but it is a widely recognized convention that makes a heavily marked document easier to read and act on.

Proofreading marks are primarily 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 is the right service for your document, read our article on what is proofreading.

The Basics of Proofreading

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 have been completed. It focuses on identifying surface errors that survived the editing process, including mistakes in grammar, punctuation, spelling, word usage, and layout and formatting.

Proofreading is not the same as copy editing or developmental editing. It does not address structural problems, argument clarity, or significant language issues. It assumes the document is already well-written and well-edited, and provides the last quality check before the document is published or submitted. For more on how proofreading fits into the broader editing process, read our guide to proofreading.

Common Proofreading Marks: A Complete Reference

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

Punctuation Marks

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

Common punctuation proofreading marks include:

Insert apostrophe. A caret with an apostrophe in the margin indicates 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 proofreading marks, as commas are among the most commonly omitted punctuation marks in unedited writing.
Insert period. A circled dot or a dot with a circle in the margin indicates 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, indicating 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. Indicated by a specific symbol in the margin, distinct from the hyphen mark. Em dashes are used to set off parenthetical information or signal a strong break in a sentence.
Insert en dash. Indicated by a specific symbol in the margin, used primarily 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 a title of a short work is missing its enclosing marks.

Operational Marks

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

Delete. Indicated by a strikethrough or a deletion symbol (resembling a looped d) through the word or words to be removed. The text marked for deletion 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 or parenthesis mark that closes the gap, indicating 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 remaining 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. Indicated by a curved line connecting two elements, or the abbreviation "tr" in the margin, this mark means the order or sequence of the marked words or letters should be reversed.
Close up space. A curved bracket or parenthesis symbol connecting two elements indicates that an unwanted space should be removed.
Insert space. A line with a hash mark (#) or a caret in the margin indicates that a space should be added between two words or elements that have been run together.
New paragraph. The paragraph symbol (¶) indicates 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. Indicates that a new 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 indicates that a previously marked correction should be ignored and the original text retained as written.

Typography Marks and Proofreading Abbreviations

Typography proofreading marks indicate 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 indicates that the marked letter should be capitalized.
Lowercase (lc). A diagonal line through a capital letter or the abbreviation "lc" in the margin indicates that the marked letter should be changed to lowercase.
Italicize (ital). A single underline under the text or the abbreviation "ital" in the margin indicates 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 indicates 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 indicates 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 indicates 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 indicates that the marked text appears in the wrong typeface or font and should be corrected.
Spell out (sp). A circle around an abbreviation or the abbreviation "sp" in the margin indicates 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 of the document carefully, marking any errors they find directly on the page. The proofreader places the correction symbol within the text at the exact point of the error, and writes the corresponding instruction or symbol in the margin alongside it. This dual marking system, one mark in the text and one in the margin, ensures that both the location and the nature of each correction are clear.

For documents going through multiple rounds of proofreading, a proofreader may mark corrections in an earlier round and then decide during a later review that the original text is acceptable as written. In that case, they use the stet mark alongside the previously marked correction to indicate that 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 the author can review every correction before the document is finalized.

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 allows you to respond accurately to editorial feedback and implement corrections precisely.

More broadly, familiarity with 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 the writing and revision process.

Get Professional Proofreading at Editor World

Editor World's professional proofreaders are native English speakers from the United States, United Kingdom, and Canada who have passed a rigorous skills test and are available 24/7, 365 days a year. Every document is returned with tracked changes so you can review and accept every correction before finalizing. Prices are transparent with an instant price calculator, turnaround times start at 2 hours, and you choose your own proofreader from our panel of verified professionals. For professional editing and proofreading assistance, contact Editor World today.