What was unique about the way children are born and infants are cared for in the community that would call a child by a number instead of a name for its first year of life?

Birthmothers, or basically women assigned to give birth to children, gave birth to all the kids in the community. They were the only people who had intercourse. These children were then assigned to the families that had submitted an application for a child. The parents essentially adopted kids instead of having their own. The children grew up and lived with their parents until they became a full adult. When they were a fully trained adult, they moved out and had a dwelling of their own.