Slots
Named regions that each hold at most one child, plus at most one unnamed child that fills the host's content when it declares one.
Every other child names the region it fills. A declaration names at least one region or declares content.
Named regions that each hold at most one child, plus at most one unnamed child that fills the host's content when it declares one.
Every other child names the region it fills. A declaration names at least one region or declares content.