What is PS?
A postscript, abbreviated P.S., is writing added after the main body of a letter (or other body of
writing). The term comes from the Latin post scriptum, an expression meaning "written after" (which
may be interpreted in the sense of "that which comes after the writing").
A postscript may be a sentence, a paragraph, or occasionally many paragraphs added, often hastily
and incidentally, after the signature of a letter or (sometimes) the main body of an essay or book.
Sometimes, when additional points are made after the first postscript, abbreviations such as PPS
(post-postscript) and PPPS (post-post-postscript) are used, though only PPS has somewhat
common usage.