PostScript

n. P.S., additional text added to a letter that has been completed and signed; additional note, additional text supplying additional information

n. language for printing and pagination used by high-quality printers (Computers)

PostScript (PS) is a page description language and programming language used primarily in the electronic and desktop publishing areas.
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A postscript (from post scriptum, a Latin expression meaning "after writing" and abbreviated P.S.) is a sentence, 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. In a book or essay, a more carefully-composed addition (e.g., for a second edition) is called an afterword. An afterword, not usually called a postscript, is written in response to critical remarks on the first edition. The word has, poetically, been used to refer to any sort of addendum to some main work, even if not attached to a main work, as in Søren Kierkegaard's book titled Concluding Unscientific Postscript.
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Noun
1. a note appended to a letter after the signature
(synonym) PS
(hypernym) note, annotation, notation
(part-holonym) letter, missive
2. textual matter that is added onto a publication; usually at the end
(synonym) addendum, supplement
(hypernym) matter
(hyponym) appendix
(part-holonym) back matter, end matter

n. postscript, P.S., additional text added to a letter that has been completed and signed; additional note; additional text supplying additional information

(n.)
A paragraph added to a letter after it is concluded and signed by the writer; an addition made to a book or composition after the main body of the work has been finished, containing something omitted, or something new occurring to the writer.