Many characters in “Better Call Saul”: Abbr.

ATTS

["Think of the three-letter abbreviation for the group that regulates lawyers in the U.S., often seen after their names."]

This clue refers to the many lawyers in Better Call Saul, a show full of attorneys. "Atts" is a common abbreviation for "attorneys," making it a short and clever fit. The show’s title character, Saul Goodman, is a lawyer, and the series features numerous others in the legal profession.