Why do some names occur deliberately? Which names were duplicated at the ceremony of ones?

Names were only duplicated at the naming ceremony if the original bearer of the name had been lost or died.

Now, at this special Naming, the community performed the brief Murmur-of-Replacement Ceremony, repeating the name for the first time since the loss: softly and slowly at first, then faster and with greater volume, as the couple stood on the stage with the newchild sleeping in the mother's arms. It was as if the first Caleb were returning.
Another newchild was given the name Roberto, and Jonas remembered that Roberto the Old had been released only last week. But there was no Murmur-of-Replacement Ceremony for the new little Roberto. Release was not the same as Loss.