Proofreading Marks and What They Mean
Proofreading marks are a shorthand of symbols that a proofreader writes on a proof to tell the typesetter or author exactly what to change. Each correction pairs a mark in the line, showing where, with a mark in the margin, showing what. The common ones cover deleting, inserting, closing up, adding space, swapping letters, starting a paragraph and leaving text as it was.
In American publishing the usual reference is the list of proofreaders' marks in the Chicago Manual of Style. British publishing works to a separate British Standard. Most proofreading now happens on screen, so the marks also have digital equivalents in Word and in PDF comments, and a working proofreader needs to read all three.
How proofreading marks work on a page
The two-part system exists so that nothing gets missed. A typesetter correcting a long proof scans down the margins, not through every line, so the margin mark is the instruction and the in-text mark is the pointer. A correction with only one half is easy to overlook and easy to misread.
In practice the in-text mark is small and precise. A caret sits below the line where something is inserted, a line strikes through a letter or word to be removed, and a curved hook joins two pieces that should touch. The margin then carries the inserted text, the symbol for the change, or both.
Several corrections in the same line are written in the margin in the same order as they occur, usually separated by a slash so they do not run together. That order matters, because the person making the changes matches the third margin mark to the third in-text mark. Clear, upright handwriting matters for the same reason.
The common proofreading marks and their meaning
The Chicago Manual of Style list of proofreaders' marks is reproduced from figure 2.6 of the 18th edition, and it is the set most American publishers and clients expect. A handful of those marks carry most of the work on any proof.
The table below shows the seven that appear on almost every page, described in words rather than drawn, with what goes in the text and what goes in the margin.
| What it does | In the text | In the margin |
|---|---|---|
| Delete | A line through the letter or word | The delete sign, a looped stroke |
| Insert | A caret below the line at the gap | The text to add |
| Close up | Curved hooks joining the two parts | The same curved hooks |
| Add space | A caret or vertical line at the gap | The # sign |
| Transpose | An S-shaped curve around the pair | tr |
| New paragraph | A bracket or caret before the word | The ¶ sign |
| Leave as it was | Dots under the struck-out text | stet, Latin for "let it stand" |
Stet deserves a second look, because it is the mark that undoes a mistake. When a proofreader or author has marked something that turns out to be correct, the dots and the margin note cancel the earlier correction without anyone having to scratch it out and redraw the line.
Type style and wording have their own marks, mostly written as short abbreviations in the margin. The ones a new proofreader meets most often are listed below.
- Capitals. Three short lines under the letter, with "cap" in the margin.
- Lowercase. A slash through the capital letter, with "lc" in the margin.
- Italic. A single line under the word, with "ital" in the margin.
- Bold. A wavy line under the word, with "bf" in the margin.
- Spell out. A circle around an abbreviation or numeral, with "sp" in the margin.
- Query. A question for the author, written in the margin and usually circled so nobody mistakes it for a correction.
The query is where proofreading judgment shows. A proofreader who is unsure whether "Smyth" or "Smith" is right asks, rather than changes it, because the author knows and the proofreader only suspects.
American and British marks are different systems
The British marks come from BS 5261-2:2005, the British Standards Institution specification for copy preparation and proof correction. Its marginal marks are symbols rather than words, so a British proof uses a mark where an American one might write "tr" or "stet".
The two sets overlap in principle but differ in shape. Both use a caret for insertion and both pair an in-text mark with a margin mark, yet a reader trained only on one will stumble over the other. An international standard, ISO 5776, sets out a shorter list of correction symbols for the same purpose.
Paper proofs are rarer now, but the British set is still expected. The Chartered Institute of Editing and Proofreading says the marks are used less than they were, but that it is reasonable for a client to expect a proofreader to know this basic tool of the trade. The practical rule is to learn the set your clients use and recognize the other.
Proofreading marks on screen
Most proofreading today happens on screen, and the marks have moved with it. Here at the Proofreading Institute, a little over four in five of the practice proofs our students marked up in the last year were marked on screen rather than on paper. The thinking behind each mark stays the same even when the tool changes.
There are two main on-screen methods. Word files are corrected with Track Changes in Microsoft Word, which records every deletion and insertion so the author can accept or reject each one. Typeset pages arrive as PDFs, and those are marked with the comment tools in a PDF reader, which let a proofreader strike through, insert at a caret, replace text and attach notes.
Each paper mark has a counterpart in both tools, set out below.
| Paper mark | In Word Track Changes | In PDF comments |
|---|---|---|
| Delete | Delete the text, shown struck through | Strikethrough tool |
| Insert | Type the text, shown underlined | Insert text tool at a caret |
| Replace | Delete and retype in one step | Replace text tool |
| Transpose | Delete and retype in the right order | Replace text, with a short note |
| Stet | Reject the earlier change | Delete the comment, or note "stet" |
| Query | A comment in the margin balloon | A sticky note beside the text |
The PDF column is the one that trips people up. A PDF proof cannot be edited directly, so every correction is a comment that someone else will carry out in the layout file, and an ambiguous comment produces a new error. Short, specific notes such as "replace with 'its'" do the job a marginal mark used to do.
Which marks a new proofreader should learn first
Learning the whole Chicago list at once is unnecessary. Most proofs need a small core, and the rest can be looked up until it sticks. A sensible order for learning them follows.
- The seven marks in the first table, until they can be written without checking.
- The style marks for capitals, lowercase and italic, which cover most consistency errors.
- The query, and the habit of using it whenever a change might alter meaning.
- Track Changes and PDF comments, practised on real files rather than read about.
- The British set, only if UK publishers or authors are likely clients.
Marks also only work alongside a record of decisions. A style sheet notes the choices a document follows, such as spelling, capitals and number style, so that a mark can point back to a rule rather than a preference. The free proofreading templates include a style sheet template for exactly that.
Knowing the marks is also part of knowing where proofreading stops. A proofreader marks errors against the agreed style and queries the rest, and the difference between that and rewriting is covered in the guide to copy editing vs proofreading.
Where the course covers marking up a proof
Unit 2 of the course, Proofreading Standards and the Work Itself, teaches marking up in Word Track Changes, in PDF and on paper, and how to tell which one a client expects. It also covers writing a query instead of making a change a proofreader is not entitled to make. That unit is part of both levels.
The Advanced course goes further with Unit 9, Tools, Workflow, and Throughput, which builds macros, wildcard searches and checklists around the errors each proofreader tends to miss. For anyone weighing the career first, the guide on how to become a proofreader covers the steps before any of that.
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