system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does a radio station send metadata like song name to my car's radio?

I was driving in my car, and for the first time noticed that the name of the current song on the radio was scrolling across the little LCD screen, and I wondered how that metadata works from the radio station's perspective.
gpt
Modulation became more efficient, which opened up space in the guard bands to transmit digital information on a sub carrier.

Edit : okay imagine that while recording the song the radio station was tapping out a special code in the background of the song that only your car radio could hear.  That code is the meta data.