Possible Clues:

• Ban competition
• Steal from telecasters and keep it to yourself
• Hidden on top of cambium in wild trees
• One not to be divulged
• With 35-Across, anonymous voting method, and a hint to each set of circled letters
• Clandestine faction assimilates religious teaching
• Hidden, private
• Like passwords, ideally
• Keep it!
• Known to few