Low-budget party letters

• Invitation notation
• Abbr. often near "R.S.V.P."
• Invitation reminder letters
• Invitation letters
• Party rule, for short
• Invite letters
• Inits. on an invitation
• Party directive, briefly
• Directive that might be near RSVP

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
initialism (acronym) for "bring your own bottle" or "bring your own booze," by 1951.