The acronyms are easy, but what about things like 🙂 or 🙁 ?
Those are called smileys. They replace the facial expression in a conversation. In a conversation body language is very important. You can often tell by looking at someone’s face if he’s serious. Over the telephone the tone of the voice can tell you more than words. When reading a letter the handwriting can indicate how important a word is. On IRC however there’s only typed text. There’s nothing like a face, a voice or handwriting. Smileys (partially) replace that. Something that can cause a lot of grief on IRC is irony. In real life you can tell if someone’s joking by looking at their body language. On IRC nothing indicates irony (except maybe for the context). Therefore a smiley is used. Smileys aren’t difficult to understand. Just lay your head on your left shoulder and you’ll see a little face. There are many smileys, but only two of them are used frequently. Here they are.