[quote=Joegreenbeen]
I need this.
[/quote]

Depends on the type/level of sarcasm, the intent, and the general message.

It's not really something that can be 'taught', so you're probably better off being a ledditor and using '/sarcasm' as a disclaimer, just make sure you believe it's because it's impossible to convey sarcasm online, and not through any fault of your own. That part is key.