Captain Jack S. Holtwick, Jr., USN is credited with establishing the Communication Technician (CT) rating for the U.S. Navy in 1948.

02.27.07 CAPT Jack Hotwitz.A
CAPT Jack S. Holtwick, USN

Because the work was accomplished by both yeoman and radioman specialties, he took the spark of the radioman rating badge and the quill from the yeoman rating badge and combined them to create the CT rating badge.  On March 25, 1976, the Communication Technicians changed to Cryptologic Technicians.

Of note: The Electronic Warfare (EW) and Information System Technology (IT) ratings can be traced back to the Radioman rating.