The answers to the clues below form a distinctive pattern. Can you determine what it is?

1. Sit-ups
2. Firm affirmative
3. U.S. chocolate company
4. Author of Harry Potter books
5. Unnamed Biblical woman who died a unique death
6. Every Good Boy Does Fine, for example
7. Musical composition, often with a number
8. Matrix barcode computer tracking system
9. Male nickname
10. Bug
11. Percussion instrument
12. One who left his mark on things

Answers:

1. Ab crunchers
2. Definite yes
3. Ghirardelli
4. JK Rowling
5. Lot's wife
6. Mnemonic
7. Opus
8. QR
9. Stu
10. VW
11. Xylophone
12. Zorro

The distinctive pattern of the answers is seen in their initial letters:

1. AB Crunchers
2. DEFinite yes
3. GHIradelli
4. JK rowling
5. Lot's wife
6. MNemonic
7. OPus
8. QR
9. STU
10. VW
11. XYlophone
12. Zorro

Credit: 
Howard Barkin
LETTERHEAD