### Question
What is the definition of unique identifier?


### Answer
The definition of **unique identifier** is as follows in *22 U.S.C. § 212b*:

> any visual designation affixed to a conspicuous location on the passport indicating that the individual is a covered sex offender

#### Citation:
  - *22 U.S.C. § 212b*
  - Heading: **CHAPTER 4-PASSPORTS**

