---
kind: "unit"
title: "50"
title_heading: "War and National Defense"
key: "ch36/schIII"
level: "subchapter"
label: "Subchapter III"
heading: "Pen Registers and Trap and Trace Devices for Foreign Intelligence Purposes"
release: "119-102"
date: "2026-07-12"
url: "https://uscodex.org/usc/50/ch36-schIII"
sections_count: 6
---

# Subchapter III — Pen Registers and Trap and Trace Devices for Foreign Intelligence Purposes

Title 50 — War and National Defense › Chapter 36 — Foreign Intelligence Surveillance

## Sections

- [§1841. Definitions](/usc/50/1841.md)
- [§1842. Pen registers and trap and trace devices for foreign intelligence and international terrorism investigations](/usc/50/1842.md)
- [§1843. Authorization during emergencies](/usc/50/1843.md)
- [§1844. Authorization during time of war](/usc/50/1844.md)
- [§1845. Use of information](/usc/50/1845.md)
- [§1846. Congressional oversight](/usc/50/1846.md)