that one : is an oooooo smilie... you can make it by using the colon then ooo and colon. Anytime you aren't sure of what a smilie is you can find out usually one of two ways: right click on the emoticon/icon/smiley and then click on properties. If it has a special name it may show up in the address. Or, such as the ones here at PC, by clicking on the smiley itself it will post the reference in your text, and all you need to do it read it.