Related Clues:

• Prejudices that prohibit the mention of something
• Prohibitions on things not to be done
• They're forbidden by religion or social custom
• Unspeakable acts
• This number and those numbers, they're all inadvisable
• They're frowned upon
• They're not allowed thanks to some scary words
• Cake and ice cream, to dieters
• They're not allowed
• Running with scissors and others
• Prohibits cheers and jeers
• Pitchers' hitless games, in baseball slang
• They shouldn't be done
• Looking back, graduate swamped by the black stuff produces societal prohibitions
• Discouraged behaviors