Related Clues:

• Words punctuating a rap
• Not always helpful reply to 'Who's there?'
• Not always helpful reply to "Who's there?"
• Possible reply to 'Who's there?'
• Knocker's proclamation
• 'You know who this is'
• Formal reply to "Who's there?"
• Overly formal self-intro
• Reply to "Who's there?"
• Formal ''Who's there?'' response
• Call from behind closed doors
• Reply at the door
• Unhelpful knock follower
• 'You know who I am'
• Exclamation upon removing a mask