Diamond belonged to "Bones," and the slap was a notification that the society had chosen Merriwell.
"I can't go now, Badger," said Frank, a bit regretfully.
Then he left the campus for his room, as each man slapped is expected to do, followed by Diamond, where he was notified formally of his election and told to appear for initiation at the society hall on Friday evening.
Of what that initiation consists no one not a member ever knows, and no member will ever tell.

Its mysteries are more impenetrable than Free Masonry..