Supplementary words in a letter

• Abbrevs. that signify "OH SHIT I forgot to write this in the letter..."
• Additions to ltrs.
• Ltr. additions
• Some afterthoughts, in brief
• Letter additions briefly
• They come after signatures in snail mail, yet before signatures in e-mail: Abbr
• Written afterthoughts
• Letter endings: Abbr.
• Tire leak sound

Wikipedia Word definitions in Wikipedia
PSS may refer to: