punctuicon
From "punctuation emoticon": A smiley used in addition to or instead of traditional punctuation, intended to introduce extra meaning on top of the literal meaning of the sentence in a nonverbal manner.
I told Mike online that he should go DIAF, but I ended my IM with a smiley punctuicon so he wouldn't think I was really that mad at him:
"Go DIAF Mike:)"
"Go DIAF Mike:)"