The Postscript That Actually Works
Ps stands for postscript, which is just shorthand for the Latin post scriptum, meaning "after writing." It sits at the bottom of a letter below your signature and lets you add something without restructuring the whole document. That is the basic definition. The interesting part is how people have used it for centuries and why it still matters in emails today. The postscript predates the internet by several hundred years. You find it in letters from the 1600s, where writers used it to include an afterthought they realized too late to weave into the main body. Jane Austen did this. Voltaire did this. They were not experimenting with marketing copy, they were just correcting the natural limitation of handwritten correspondence: once you finish writing, you cannot go back and insert a paragraph without making the page look like a mess. In the commercial world, the postscript got weaponized. Mail-order catalogs in the 1970s and 80s were the first to realize that readers often skip straight to the bottom. A direct mail piece I worked with in the mid-2000s had a bare-bones body because the designer thought readers would skim anyway. We added a single line in the Ps that repeated the limited-time offer with a different angle. Response rate went up roughly 18 percent. That is not a small number when you are mailing hundreds of thousands of pieces.
The mechanics are straightforward but people still misuse them. When you write a Ps, you are interrupting the reader at the moment they think they are done. The brain registers the letter as complete once it sees the signature. A postscript breaks that closure and forces re-engagement. That is why it carries more weight than an extra paragraph in the middle, where attention naturally thins out. I ran into a specific problem with a client proposal a few years ago. The main proposal was locked and printed. The legal team added a compliance footnote after everything was finalized, but the client never saw it because they stopped reading at the conclusion. I could not change the printed pages. Instead, I added a single line in the Ps on the transmittal email that referenced the footnote and linked to the full compliance document. The client replied within the hour and approved. That workaround existed because the postscript lives outside the formal document structure but still travels with it. Here are the practical nuances that most people miss. First, do not write a second body in your Ps. A long postscript defeats the purpose and becomes its own paragraph that nobody reads. Keep it to one or two lines maximum, maybe three if the point genuinely requires it. Second, the Ps works best when it does something the body does not: it can restate the ask, add a personal note that feels separate from the formal text, or provide a time-sensitive detail that changes the calculus. Third, in business correspondence, a well-placed Ps can subtly shift power dynamics. The person who writes the Ps controls the final impression.
There are situations where the postscript fails entirely. If the recipient is a gatekeeper or an automated filter, the Ps gets ignored along with everything else. In formal legal documents, adding a postscript can create ambiguity about whether the appended text is part of the executed agreement. I have seen contracts challenged because one party argued the Ps constituted a material modification that was never properly countersigned. If you are dealing with anything that has legal weight, put the information in the body or in an exhibit, not in a postscript. Another limitation that people overlook is digital fatigue. Every inbox is cluttered, and many readers have trained themselves to ignore everything below the signature line. A Ps in an email only works if it is genuinely different from the preceding text. Restating the same call to action in slightly different words usually gets skipped. The effective Ps adds new information, not recycled information. The tool itself is trivial. There is no software you need, no special format required. You type P.S. or just Ps at the bottom and add your line. Some style guides prefer one dot after the S, some prefer two. The difference is cosmetic. What matters is the placement and the content. If you are sending something through a template system that auto-appends disclaimers below the signature, your Ps goes before those disclaimers, not after them. Anything below a boilerplate disclaimer looks like noise.
Get the Full Details
For reference documents or templates, I keep a simple file with a few proven Ps structures for different scenarios: the reminder, the personal note, the urgent update, and the soft close. Each one is two lines or fewer and written in a distinct voice from the body. When I need one, I copy the relevant template and adjust the specifics. This saves probably ten minutes per message compared to drafting from scratch, though the real value is consistency across a high volume of correspondence. There is no download link for the postscript. It is a convention, not a product. If you want a starting point for your own use, write your letter normally, add your signature, then force yourself to answer one question: what is the single most important thing the reader should remember after they finish? Whatever that is, put it in the Ps. If you cannot answer that question clearly, the Ps will be weak and the reader will feel it.
