Answer: pps

AnswerCrossword Clue
PPSLetter writer's afterthoughts: Abbr.
PPSAfterthought afterthought (abbr.)
PPSSecond notation at the bottom of a letter
PPSSecond letter addendum
PPSAfterthoughts on a ltr.
PPSShort after-after-thought
PPSLetters ending some letters
PPSLetter-extending abbr.
PPSSecond afterthought (abbr.)
PPSAdditional afterthought, for short
PPSAfterthoughts: Abbr.
PPSEnd-of-letter letters
PPSLtr.'s second add-on
PPSLetter abbr.
PPSSecond ltr. addition
PPSSecond addition to a ltr.
PPSSecond ltr. addenda
PPSSecond ltr. addendum
PPSSecond afterthought
PPSLetter extender
PPSLetters that further extend letters
PPSLtr. addendum
PPSSheets in a mag
PPSLetter addendum
PPSLast thought in a ltr.
PPS"And one more thing,..." (abbr.)
PPSAfter-afterthought
PPS2nd afterthought
PPS2nd letter add-on
PPSAfterthought afterthought: Abbr.
PPSEnd-of-letter abbr.
PPSLetter letters
PPSSecond afterthought: Abbr.
PPS"Almost forgot...": Abbr.
PPS"Oh, and another thing," on a ltr.
PPSSecond afterthought, in a ltr.
PPSForgetful writer's letters?
PPSCorrespondent's "Oh, and another thing ..."
PPSLtr. extender
PPSLetters before a second afterthought