RDS may be one of the smallest signals your FM station transmits, but getting it right matters more than ever. On Episode 804 of *This Week in Radio Tech*, broadcast network engineer and podcast host, Tyler Woodward, explains the technical details behind RDS and its U.S. counterpart, RBDS. We discuss the data fields every FM engineer should understand, including PI codes, program type, alternate frequencies, and the way field repetition rates affect what listeners see on their radios. Tyler also explains why accurate PI codes are increasingly important for connected-car services such as RadioDNS and dts AutoStage—and points broadcasters to a useful online tool for verifying the correct PI code for their call letters. If you are responsible for an FM station, this is a must-listen—or must-watch—conversation.