Fetching details from the dictionary...
postscript; post scriptum; PS; P.S.
追伸に一言書き足した。
I added a quick note to the postscript.
結局、一番大事な用件は追伸に書かれていた。
In the end, the most important matter was written in the postscript.
彼は追伸で、猫の安否を尋ねた。
In the postscript, he asked about the cat's well-being.