Educational advertisement, for short

PSA

Think of the three-letter acronym that promotes awareness on TV or radio.

This clue is looking for a short way to say "public service announcement," which is a message meant to educate people about important topics like health or safety. The word "advertisement" hints at it being a promoted message, while "for short" signals the answer is an abbreviation. "PSA" fits perfectly as the common three-letter shorthand for these informative ads.