Kind of hotel, for short

• Sign for a Broadway hit (abbr.)
• Sign scalpers adore
• Sign at a hit show
• Box office sign, briefly
• Marquee sign
• Packed house, initially
• Lobby sign
• Sign of a seating shortage
• Sellout sign abbr

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1941, initialism (acronym) for standing room only.