Custom Facebook Emoticons

People wants emoticon. And whenever the chatting system does not allow to customize them, they start to complain.
Think of Skype. They sometimes add 2-3 new emoticons, and people starts again ranting.

Another place where I have been watching people asking for custom emoticons is Facebook. Many hoaxes came around, like "spam this page to everyone in the world and you'll receive custom smiles!", but few know that a custom emoticon system is already there.

Further, we all have a custom emoticon of ourselves!

Try this. I want a trollface emoticon to add into chat message. I search for a page and find this one:
https://www.facebook.com/pages/Trollface/313306795360291

Now, I note that there is a numerical code in it: 313306795360291

If in the chat board I type [[313306795360291]], this emoticon will show up:  

If you try with a personal page, you might find a link like:
http://www.facebook.com/profile.php?id=NUMBER

Again, use [[NUMBER]] and you will get that person's emoticon!