All I can say is, cheating through a computer is ridiculous, but unfortunately it happens.
And like I mentioned of other stuff happening, they can also be messing around with someone not on-line and totally stabbing you in the back.
For a much bigger list the WBS Chat Book has a whole list compiled from various users from all over including various smileys!! If you choose you can use text editing to increase the size of your text to catch someone's attention.
This is most of the list from that place: AFAIK As Far As I Know AFK Away From Keyboard ASAP As Soon As Possible BBL Be Back Later BBN Bye Bye Now BBS Be Back Soon BEG Big Evil Grin BF Boy Friend BRB Be Right Back BTW By The Way BWL Bursting With Laughter C&G Chuckle and Grin CID Crying In Disgrace CNP... This can make your messages in bold, italics, or color.
In IRC's you can only type in all capitals, there is no text editing.
When in IRC chats there's the "/me" command to do your actions.
Just type it in like this: /me your action here, and it will print out your name and the action you just did.
It is another way of getting another chatter to talk to you, but it is considered to be rude unless you have no choice to, which is usually when no matter what you have said in the chat, everyone is still ignoring you even though you have not typed anything rude or insulting.
Chat Abbreviations To cut down time on typing, many people have started using abbreviations for various actions and phrases.