### Question
How does the law define national security letter?


### Answer
Under *50 U.S.C. § 1874*, **national security letter** is defined as:

> given that term under section 1873 of this title.

#### Citation:
  - *50 U.S.C. § 1874*
  - Heading: **CHAPTER 36-FOREIGN INTELLIGENCE SURVEILLANCE > SUBCHAPTER V-OVERSIGHT**

