Invitation advisory, or a homophonic hint to the starred answers' starts

• Party rule, for short
• Invitation abbr. concerning drinks
• Abbr. often near "R.S.V.P."
• BBQ invite letters
• Abbr. on some invitations
• Inits. on a party invitation
• P.S. on an invitation
• "We won't be bartending"
• "We're not serving liquor," briefly

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) ...