Your Guide to Proofreading Marks

Proofreading marks, which are also called “proofreaders’ marks,” “proofreading marks,” and “editing marks,” signify mistakes in printed copy. Proofreaders and editors generally use a red pen to note them on the page. 

Though much editing, like the editing done here at EditorNinja, is now done digitally within shared docs and other word processors, written proofreading marks are still vital to all kinds of students, teachers, freelancers, and publishers.

Looking for proofreading services? EditorNinja’s professional proofreading services can save you hours of time per week, so you can focus on things you love more. Schedule a free Intro Call to learn more. And if you’re a proofreader looking for work, apply to EditorNinja’s extended network of writers and editors.

All the Proofreading Marks That are Fit to Print

Here’s a list of some of the most common proofreading marks, culled from well-established sources like Northwestern University and the Chicago Manual of Style. 

Close space
Insert space
or  Insert
Insert period
Insert question mark or exclamation point
Transpose letters, words, or phrases
New paragraph
Insert hyphen
Insert en dash
Insert em dash
Insert parenthesis
Spell out (numbers or acronyms)
Wrong word
Too wordy
Word choice
Run-on sentence
Change a letter
Wrong font
Make italic
Make bold face
Make light face
Make roman (not italic)

Two Proofreading Symbols — In Text and In Margin

Lastly, you should know that many proofreading marks have both a textual mark and a marginal mark. 

  • A textual mark means that the symbol is written on the text to be changed
  • A marginal mark, which is placed in the margin, is a symbol or abbreviation that explains the textual mark. 

However, many editors may forgo the marginal mark, and in many cases, the “marginal” mark will be written immediately above or below the text. (Yes, there’s a reason your teachers always wanted those essays double-spaced.)

Proofreading Marks have Wiggle Room

Now, proofreading marks do not comprise a hard science. Though most “official” organizations, like style guides and big publishing houses, agree upon a number of symbols, there’s plenty of wiggle room—meaning, you will find a lot of variation among sources. 

To illustrate the point, let’s consider insertion, i.e., putting in a missing letter or a bit of punctuation. 

While, in theory, many kinds of insertion have their own particular symbols, these rules aren’t always followed in practice. For example, to insert a period, most guides will say the proofreader should draw a period with a circle around it, but to insert a letter or word, a carat (^ or ⌄) is used, and further, to insert a parenthesis, the proofreader will write a parenthesis with two horizontal lines through it. 

However, proofreaders and editors may not always follow these individual rules. Instead, they may use circles or carats at will, or they may only write what they want to be inserted without any extra symbols at all.

Additionally, publishers, editors, and English teachers often have their own systems of proofreading symbols. Personally, I use arrows when I find that material needs to be reorganized, and, following in the footsteps of my middle school English teachers, I will use the abbreviations “CD” and “CM” for “concrete detail” and “commentary.” (Shoutout to Mrs. Randall.)

Proofreading Mark Examples & Symbols in Context

Below you’ll see a sheet with all the symbols with examples of their usage, as well as what the edited text would look like. (Or, in some cases, might look like — though inserting a period or fixing a word’s spelling is pretty objective, responding to a comment like “awkward” or “too wordy” is more open-ended.)