1. (noun) a note appended to a letter after the signature

• ps

2. (noun) textual matter that is added onto a publication; usually at the end

• addendum
• supplement

1. (noun) a note appended to a letter after the signature

• annotation
• notation
• note

2. (noun) textual matter that is added onto a publication; usually at the end

• matter

1. (noun) textual matter that is added onto a publication; usually at the end

• appendix
• continuation
• sequel

1. (noun) textual matter that is added onto a publication; usually at the end

• add on
• affix
• append
• supplement
• supplemental
• supplementary