Answer:

pps

Answer	Crossword Clue
PPS	Letter letters
PPS	Sheets in a mag
PPS	Letter addendum

PPS	Last thought in a ltr.
PPS	"And one more thing,..." (abbr.)
PPS	After-afterthought
PPS	2nd afterthought
PPS	2nd letter add-on
PPS	Afterthought afterthought: Abbr.
PPS	End-of-letter abbr.
PPS	Ltr. addendum

PPS	Second afterthought: Abbr.
PPS	"Almost forgot...": Abbr.
PPS	"Oh, and another thing," on a ltr.
PPS	Second afterthought, in a ltr.
PPS	Forgetful writer's letters?
PPS	Correspondent's "Oh, and another thing ..."
PPS	Ltr. extender
PPS	Letters before a second afterthought

PPS	Second afterthought abbr.
PPS	End-of-letter letters
PPS	Afterthought afterthought (abbr.)
PPS	Second notation at the bottom of a letter
PPS	Second letter addendum
PPS	Afterthoughts on a ltr.
PPS	Short after-after-thought
PPS	Letters ending some letters

PPS	Letter-extending abbr.
PPS	Second afterthought (abbr.)
PPS	Additional afterthought, for short
PPS	Afterthoughts: Abbr.
PPS	Letter writer's afterthoughts: Abbr.
PPS	Ltr.'s second add-on
PPS	Letter abbr.
PPS	Second ltr. addition

PPS	Second addition to a ltr.
PPS	Second ltr. addenda
PPS	Second ltr. addendum
PPS	Second afterthought
PPS	Letter extender