A chat symbol is something used for or representing an item or a thought while sending messages back and forth in a chat session. Chat symbols can be in the form of an abbreviation or an emoticon. An emoticon is a method of showing an emotion on the Internet and in text-based communications, such as e-mail, chat and SMS.
Emoticons, short for emotional icons, are letters or symbols used on the keyboard that represent feelings, such as a smiley face to show happiness or a wink for flirtation. According to Computer Hope, the smiley face chat symbol is often credited as being first suggested by Professor Scott Fahlman on a bulletin board on September 19, 1982.
ChatSlang.com is a useful resource for learning the meaning of many chat symbols, acronyms and emoticons. There are seasonal emoticons related to different holidays and events, such as Valentine's Day, Christmas or a birthday. All chat symbols are commonly read sideways from left to right. Chat terms such as "BRB" for be right back or "LOL" for laughing out loud are easily distinguishable to most people. The list of chats symbols is ever growing and there does not seem to be a particular formula for creating them other than being creative.