What is "htlingual"

HTLINGUAL (also HGLINGUAL) was a secret Central Intelligence Agency project to intercept mail destined for the Soviet Union and China that operated from 1952 until 1973. Originally known under the codename SRPOINTER (also SGPOINTER), the project authority was changed in 1955 and renamed. Early on, only the names and addresses appearing on the exterior of mailed items were collected, but they were later opened at CIA facilities in Los Angeles and New York.

The program’s stated purpose was to obtain foreign intelligence, but it targeted domestic peace and civil rights activists as well. Mail to and from prominent individuals such as Bella Abzug, Bobby Fischer, Linus Pauling, John Steinbeck, Martin Luther King, Edward Albee, and Hubert Humphrey was opened over the course of the operation.