From "The Rockford Files: To Protect and Serve: Part 1 (#3.19)"
Just what is a buff?
] Buff? Well... well, it's a citizen who is uh, fascinated by police work. Like, you know, people who are into CB radios and Broadway shows. These people are "buffs" as we call them. They like to spend time around the station house, get to know the fellas, sorta hang out...
[not looking amused
] Dennis, that's not a buff, that's a groupie!