Smile Emoticon
Emoticons are pictograms representing emotions. The most popular emoticons are :) ;) and :( which may also be rendered :-) ;-( and :-( these pictograms mean "happy/smiling", "wink/joking" and "sad" respectively. Emoticons are a modern invention, but not without historical antecedent. The modern emoticon :-) was originally proposed as a delimiter for jokes, to avoid confusion on Carnagie-Mellon University's bulletin board systems.
There are a large number of other emoticons ranging from the stupid to the idiotic. Emoticons are illiterate constructs, often used as an substitute for expressiveness in writing and are best avoided, even in the most informal communications.
Emoticons are also available to represent types of sex, cartoon characters, animals and plants, types of buttocks, types of breasts and Japanese thought/culture.
Many email clients, fora, blogs and other software systems can convert textual emoticons into graphic icons and may do so automatically, this can result in confusion. Many fora have proprietary communities with extensive groupthink reinforced by emoticon conventions which may vary from standard use.