Eighty-Eight

Eighty-Eight is an internet slang term used to indicate “bye-bye” or “goodbye.” It’s typically used to express farewell or to indicate that someone is leaving a conversation or a group.

Examples:

After chatting for hours, I told my online friend, “It was nice talking to you! Eighty-Eight!”
When leaving an online gaming session, the player typed in the chat, “Alright guys, I gotta go. Eighty-Eight!”