When one says something in a bragging manner, and realizes that he is bragging, he may 'call' himself out on this brag, by adding the expression, "self-call" to the end of his statement. It can also be used to call someone else out in their bragging.
I am the best basketball player in the room, self-call!
"A" says, "I'm a great cook."
"B" replies, "Nice self-call"