Brown-bagging letters

• Invitation abbr. concerning drinks
• Letters on a party invitation indicating that booze won't be provided by the host
• "We're not serving liquor" party invitation notice: Abbr
• Invitation abbreviation
• Letters of invitation?
• Letters on some invitations
• "We won't be bartending"
• Caveat on a cheapskate's BBQ invite

Wikipedia Word definitions in Wikipedia
BYOB is an initialism used on party invitations, meaning "bring your own beverage" or variants. BYOB may also refer to: BYOB (musician) , an English musician B.Y.O.B. (song) , a song by System of a Down from their album Mezmerize BYOB (programming language) ...

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.