Another of the Humanism Core Principles is relevant here...

Children shall not be subjected to physical and mental abuse, nor to religious or political indoctrination by parents or others. The rights of children should be codified in a charter of children's' rights.

While parents, guardians and elders have a responsibility towards their children (and vice versa) this responsibility does not give a carte blanche for them. Today most legal jurisdiction interdict physical and sexual abuse of children by anybody including parents. This is as should be. But what the law does not do is to prevent the political and religious indoctrination of children. Religions are allowed to conduct ceremonies like Baptism in Christianity, circumcision in Judaism and Islam and the thread ceremony of Hinduism. Children are incapable of understanding what is done to them in such ceremonies. Humanists should deny the existence of such rights for parents, priests and the like. This rule does not mean that children should not be inculcated in ethical standards. But these should be a basic non-religious kind of ethical standards. There is still no formal charter of Children's' Rights. The biggest impediment to the creation of such a charter will come not from theists who will not give up their right to automatically impose their religion on their children.
It doesn't say anything about teaching ALL religions to children, which is what I will personally be doing - so I don't agree completely with this statement. But the part about religious groups feeling it's their right to impose their beliefs onto children is just so true - its a general assumption that this will happen if you belong to one of those groups. But I do agree with the part about only teaching basic ethical standards to a child which are non religious - Athiests and the like do this anyway - at least that's how I was raised.