Quotable bit on a movie poster

• "Just do it" for Nike
• "In space no one can hear you scream," for "Alien"
• Catchphrase
• Catchword; slogan
• Nike's is 'Just Do It'
• Identifying phrase
• "She walked off the street, into his life and stole his heart," for "Pretty Woman"
• Something funny in setting of gelatin

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
"punchline of a joke," 1926, originally "last line in an actor's speech" (1916), from tag (n.1) + line (n.).

Wiktionary Word definitions in Wiktionary
n. 1 The punch line of a joke. 2 (context computing English) A pithy quote habitually appended to a signature, used as an advertising slogan, etc. 3 A line attached to a draft of cargo or a container to provide control and minimize pendulation of cargo ...