"BRB, someone's at the door." BRB stands for "be right back." It is one of the oldest internet acronyms, dating back to the 1980s and 1990s chat rooms. It tells the other person you are stepping away, but you intend to return. It is polite. It prevents the other person from thinking you are ignoring them. It is a tiny promise.

In gaming, BRB is a common chat message. You leave your character in a safe spot, type BRB, and go get a snack. In text messages, it is less common. The expectation of constant availability has made "BRB" feel almost formal. Some people just stop replying. Others use it to signal a short pause. The word is not dead. It is just old.

Related acronyms

• BRT: be right there.
• AFK: away from keyboard, a longer absence.
• TTYL: talk to you later, a goodbye.
• GTG: got to go, a departure.

BRB is a courtesy. It says "you matter enough for me to tell you I'm leaving." In a fast chat, it keeps the conversation alive. In a slow one, it is unnecessary. The acronym is small. The social function is large. It is a micro-negotiation of attention.