"I'm not providing, you drunks!"

• Like many restaurants without a liquor lic.
• Party invite initials, sometimes
• Letters on some invitations
• Quartet often near RSVP
• Party rule, for short
• Abbr. often preceding 29-Down
• Party abbr. about drinks
• "No alcohol provided" letters
• Party directive, briefly

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.