"Shlita" is customarily added to the name of a living rabbi or leader, either in addressing or speaking/writing about him. It is often written as an acronym, as in "shlit"a" or שליט׳׳א. As an acronym, it's a blessing for a long life. Why, then, should its usage be limited to rabbanim (other than the fact that the non-acronym form (שליטא) means "leader")? Is it improper to use it for someone who is not a leader?
A related question: What does שליט"א stand for?
