When friends don't understand what your abbreviations stand for during online chats or texts, 'immoa' can be used as a response which means "I make my own abbreviations." It can also be used in a sarcastic way if a friend doesn't understand a simple abbreviation.
Richard: what do you think of my new phone?
you: idl it.
Richard: what was that?
Richard: what's that!??
you: i make my own abbreviations..
*idl: I don't like
Richard: I farted really loud today in last period!!XD
Richard: what is that??
Richard: fine. I'll go look it up.