Or emoticons. Text faces. Character expressions. What ever you want to call them. But the thing is, they’re cropping up more and more often. You have your standard sideways smiles 
and your upright ones ^_^ ^.^ ^_~ . There’s a variety of sad faces 
T.T ;_; too. And then all those involving looking at someone oddly, squinting, laughing, surprise, or embarrassment. But I do like this one < 
Poor kids a dunce!
I could go on and on about when emoticon to use when, but the bigger issue I believe is when to use them at all.
Don’t ever use them for professional writing. Professionals are well….professional and that usually includes have a good handle on their emotions when talking to people. And considering that smileys expression emotions, you get the drift. It’s also important to consider that many people you work with simply wouldn’t understand the symbol you use, especially if you do not stick to the most common ones. Emoticons were developed by young people, and such are still being tailored by them. So you’re welcome to use them when talking to friends in causal conversation, use them in Facebook posts. But keep them out of e-mails to your boss.