Related Clues:

• Cultivate oregano on edge of allotment? That's to be avoided!
• Talking during a movie, e.g
• 'That's a ___'
• Bar bill ending with two zeros
• Forbidden fruit, a book about it
• Playing with matches, e.g
• Prohibition also covers one naval seaman
• Voluntary lot audibly disapprove of ritual restriction
• Proscribed practice
• Hasbro's 'game of unspeakable fun'
• It might be barricaded, so you'll have to pee elsewhere
• Strictly off-limits
• 'Tsk, tsk' elicitor
• Asking 'When's the baby due?' without knowing for sure the person you're asking is pregnant, for example
• Brief thanks and cry of contempt forbidden