As a convention of writing, punctuation helps writers and readers more clearly understand written language. There are six rules for using slashes as punctuation marks in written American English:
- In fractions
- In dates
- With abbreviations
- Separate alternatives
- Indicate line breaks
- With file names and Internet addresses
Forward Slashes in Fractions
Do not place a space before or after the slash in a fraction.
Forward Slashes in Dates
Use a forward slash to separate the month, day, and year, in an informal representation of a date. For example:
Do not place a space before or after the slash in a date.
Forward Slashes with Abbreviations
Use a forward slash with certain abbreviations. For example:
- c/o (care of)
- w/ (with)
- w/o (without)
Use a forward slash to abbreviate the word per. For example:
- miles/hour (miles per hour)
- seconds/minute (seconds per minute)
- weeks/year (weeks per year)
Do not place a space before or after the slash in an abbreviation.
Forward Slashes to Separate Alternatives
Use a forward slash to separate alternatives. For example:
Do not use a slash to join coequal nouns; use a hyphen instead.
Forward Slashes to Indicate Line Breaks
Use a forward slash to indicate line breaks in quotations of less than four lines of poetry. For example:
- Shel Silverstein ends his poem “Where the Sidewalk Ends” with a walk: “Yes we’ll walk with a walk that is measured and slow, / And we’ll go where the chalk-white arrows go, / For the children, they mark, and the children, they know / The place where the sidewalk ends.”
- “I heard a Fly buzz – when I died – / The Stillness in the Room,” begins “I heard a Fly buzz – when I died” by Emily Dickinson.
Place a space before and after a slash that indicates a line break in a poem.
Forward Slashes in File Names and Internet Addresses
Use a forward slash in computer file names and Internet addresses. For example:
Do not place a space before or after the slash in a file name or Internet address.
Although the term “back slash” is often used to refer to the slashes in URLs and other computer files and addresses, the back slash (\) is not actually a punctuation mark found in written English. Instead, the back slash is a typographical mark used primarily in computer language. As such, the back slash should not be used in written American English except in an example of computer code.
Punctuation marks, as a convention of writing, help to make reading and writer easier by ensuring the clarity of written language. Slashes perform four basic functions in written American English: in fractions, in dates, with abbreviations, the separate alternatives, to indicate line breaks, and with file names and Internet addresses.
Faigley, Lester. 2003. The Brief Penguin Handbook. New York: Pearson Longman.
Gibaldi, Joseph. 2003. MLA Handbook for Writers of Research Papers. 6th ed. New York: The Modern Language Association of America.