Pen register

{
  "id": "MLC-T-LAW-003691",
  "term": "Pen register",
  "field": "Law",
  "definition": "A device or program that records the outgoing telephone numbers dialed from a particular line. It captures metadata about communications, such as the numbers called and the time of the call, but does not record the content of the conversation. In the United States, law enforcement agencies must obtain a court order to install and use a pen register.",
  "url": "https://mlchart.com/terminology/law/pen-register/"
}