1. I am not entirely a back number, Taylor.

2. He is a back number.

3. Never mind about him, he's a back number.

4. This building has become a back number in design.

5. Never mind about him. He's a back number.

6. Maybe I'm a back number. I can never enjoy a play of staccato scenes.

7. It does not matter. It was a back number anyway.

8. It doesn't matter , It was a back number anyway.