Acronyms like “BSF” spread for a simple reason: communication becomes cheaper in time and effort. Online spaces—especially mobile messaging—encourage quick replies, and people adapt by compressing common phrases into a few letters.
“Best friend” already exists as a social concept. Once a shortcut becomes familiar, it keeps repeating. That repetition builds momentum: even people who are new to a community often pick up “BSF” because they’ve seen it used successfully in the same way.
But acronyms also evolve. Different communities can reuse the same letters for different meanings. That’s why you can see “BSF” with one meaning in your friend group and another meaning in a totally different online space.
