PS, Parthian shot, accession, accessory, accident, accidental, accompaniment, addenda, additament, addition, additive, additory, additum, adjunct, adjuvant, afterthought, annex, annexation, appanage, appendage, appendant, appendix, appurtenance, appurtenant, attachment, augment, augmentation, auxiliary, back matter, chorus, coda, codicil, collateral, colophon, complement, conclusion, concomitant, consequence, contingency, contingent, continuance, continuation, corollary, double take, dying words, envoi, epilogue, extension, extra, extrapolation, fixture, follow-through, follow-up, happenstance, incidental, increase, increment, inessential, last words, mere chance, nonessential, not-self, offshoot, other, parting shot, pendant, peroration, postface, postfix, postlude, postscript, refrain, reinforcement, rider, second thought, secondary, sequel, sequela, sequelae, sequelant, sequent, sequitur, side effect, side issue, subscript, subsidiary, suffix, superaddition, supplement, swan song, tag, tailpiece, undergirding, unessential