It is the result of FBI check

instead of fingerprint that expires every 15 months. In the past INS throws yourfingerprint once being submitted to FBI. Once the result is expired, they asked you to do the finger print again. Last year they discussed to store fingerprint for future use (extra FBI check, EAD card, and GC card). They may already have the technology storing finger print right now. Let's see what happen in the future.