No, an emoticon is not a sign, but it is part of the course. Today, we communicate daily using that most insipid of communication tools, namely the text message, where not only do we shorten words, "u" instead of "you' and such, but we also communicate by a new language of symbols and abbreviations, such emoticons and acronyms, like LMAO (In a recent episode of "The Neighbours" a mother intercepted a text message between a boy and her daughther misconstruing LMAO for "Let My Ass Out"). Thus as technology develops and we spend less time on communication, we resort to inventing a new kind of language, consisting of symbols and abbreviations that, if presented to an outsider, is either nonsense or can be easily misconstrued. It goes beyond the mere labels of argot or slang, it is a language in constant development and change, being created and reformed on a daily basis by not just a population but the global population. Take for example 5555 which,as we all know, means "to be crying" within China, outside of China it means five-thousand, five hundred and fifty-five. Except when I write it to a friend in Denmark and explains it, he writes it to another friend and before long a chap in Denmark, Australia, China and Spain are incorporating it into their cyber-speak. I recently read that someone was heavily into planking inspired by an Internet meme...I can understand Shakespeare but that sentence made no sense. It was English, the people who commented on the sentence wrote in English but I, an English teacher, thought it was gibberish. I will continue researching on Google.