"I'll return shortly," in a text

• Texter's "Hang on a minute"
• Texter's "Gimme a sec"
• Palindromic "Hang tight" text
• "Hold on a sec," in texts
• "Give me a sec," in texts
• "Gimme a sec," in chats
• "I need to step away for a sec," in an IM
• "I'll return in a minute," in instant messaging shorthand

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
by 1996, Internet chat acronym for be right back .

Wiktionary Word definitions in Wiktionary
init. (alternative case form of BRB nodot=1 English) (gloss: be right back).