Proscribed
Else clues • 49 + 51: 101? To start with, that's wrong (7)
• Against the rules
• Backdoor
• Contraband
• Forbidden
• Like hanky-panky
• Like racketeering
• Not kosher
• Not permitted
• Prohibited
• Shady
• Unauthorized
• Under-the-table
• Unlawful