!=

Do you know what that means?

I use it everyday at work. I use it so much that I even think of what it means in Engrish when I use it. I'll give you a hint. It is something I type and it is not an emoticon. Give up?

It means "does not equal". If you are not a programmer there is no reason for you to know that. However, I am a programmer, and it is a very useful tool. And now you know it too.