PS, or postscript, is used to denote a sentence, idea, or paragraph appended after the main body of a letter or text. It comes from the Latin postscriptum which translates to “written after”. According to Dictionary.com, the word came into English from the early 1500s.
The dictionary states as one definition that postscript is, “a paragraph, phrase, etc., added to a letter that has already been concluded and signed by the writer.” However, in electronic communication, such as email, the PS is sometimes placed before the writer’s signature. Yet, in every case, it is added after the main body and expresses supplementary information.
There are situations where you might want to include more than one postscript. This would usually be if you have 2 or more separate pieces of supplementary information to append. So how do you add multiple postscripts? Do you only insert a PS before each paragraph? Do you add an ‘S’ to each new PS? Or do you add a ‘P’ to each new PS? That is, should the second postscript start with PSS or PPS? Or are both acceptable?
To figure out which form is correct, let’s break down the word postscript. English has many affixes – pseudo-words that attach to the beginning (called a prefix) or the end (called a suffix) of another word and change the meaning of the attached word. These affixes by themselves do not have any meaning; they are not considered words on their own.
Some examples of prefixes in English are in-, de-, and un-. All three of these express negation of some sort. Compare ability vs. inability, claw vs. declaw, and attached vs. unattached. Two examples of English suffixes are -ing and -ed. They both change the tense of a verb, with -ing expressing the present continuous tense, and -ed expressing the simple past tense.
Now while post is a word by itself, being used as both a noun and a verb, is it also a prefix. As a prefix it expresses the ideas of “behind”, “after”, “later”, “subsequent to”, or “posterior to”. So postscript literally translates to “after (the) script”.
How does this help us determine whether to write PPS or PSS at the start of a second postscript? PS is just a shortening of postscript. Now since postscript means “after (the) script”, a second postscript would only logically be “after after the script”, or twice behind the main text. “After after the script”, or post-postscript would then shorten to PPS.
The same would apply to further addendums. Each new postscript would have to begin with another P added to the PS. So if you ever see PSS, you now know that short-form does not exist in English because it would mean postscript-script, which of course makes no sense.