What “PS” Means and How to Use It Correctly

In the days before email, Paul McCartney famously sang, “PS I love you” on The Beatles’ 1963 album, Please Please Me. But what does PS mean and how do we use it in modern communication?

PS meaning: What does PS mean in letters?

PS is an abbreviation for “post script” used for additional information at the end of a letter or message that doesn’t relate to the main topic. For example, you might write an email to your friend and then add a line after your signature that reads, “PS – I’m having a party this weekend and want you to come.” PS comes from the Latin phrase postscriptum, which means “written after.”

In the days of handwritten and typed letters, we often found ourselves remembering something we wanted to include only after we’d signed off. That’s where a PS came in handy. It’s also often used for effect to add a clever or funny afterthought. It can be added for emphasis, or even as an argumentative “So there!” It’s a tool still used in direct and email marketing, which we’ll talk about in a moment.

The P.S. is the most charming part of a letter. It’s the wink you give as you walk away.

—Shaun Usher, author of Letters of Note, for The Wall Street Journal

How to punctuate and format PS

Should PS be capitalized? How is it abbreviated; with (P.S.) or without (PS) periods? Should you use any trailing punctuation? Surprisingly, there are no hard and fast answers to these questions.

The Cambridge Dictionary suggests that PS is the proper format in British English.

The Cambridge Dictionary also says that P.S. (with periods after each letter) is the American English format. Indeed, you’ll often find it abbreviated as such in the US. But The Chicago Manual of Style favors PS, without the periods.

The verdict? Usage varies, and PS doesn’t factor into most style guides. The safest bet is to capitalize the P and S (use periods after each letter if that’s your preference), and leave out any trailing punctuation.

PS in email

PS once saved us from having to edit or rewrite an entire letter just to include an important afterthought. But email allows us to go back and edit before sending. Technically, we could avoid the use of PS altogether in electronic communication. But should we?

Not really. PS is still useful for effect, and it’s a great way to get a specific point noticed. Although the Internet has made us a culture of skimmers rather than people who read things like email word-for-word, we tend to notice what’s at the beginning and end of a text. 

Including a PS has long been a direct mail marketing strategy. Statistics once showed that as many as 79 percent of people who opened a direct mail letter would read the PS first. Although times have changed, email marketers still swear by it as a way to reiterate a call to action, create FOMO, provide some sort of bonus information or offer, or even share a testimonial.

Examples of PS in a letter

To demonstrate just how effective a PS can be, here are some examples from letters written by famous and notable people. 

John Lennon

We opened this article with The Beatles, so let’s return to that theme for a moment. Here’s a letter John Lennon famously wrote to a groupie who dissed Yoko Ono. This PS isn’t exactly an I love you.

Ronald Reagan

This excerpt comes from a letter Ronald Reagan penned to his son, Michael, in 1971, shortly after Michael was married.

Philip K. Dick

In 1973, four years before it was published, Philip K. Dick sent his agent, Scott Meredith, an outline of his novel A Scanner Darkly. This cover letter includes an enthusiastic PS.

Richard Feynman

Influential American physicist Richard Feynman (a 1965 Nobel Prize winner) lost his wife and high school sweetheart, Arline, when she died of tuberculosis at age 25. In October 1946, sixteen months after Arline’s death, he wrote her a tender love letter, which remained in a sealed envelope until after his death in 1988.