Normal
It is really a rule and as I said above, I have personally known people who have been denied boarding because of this. I have also had to deny boarding to passengers when I worked at the airport because they could not produce this information.If the other parent says no, then theoretically the child would not be able to go.If the other parent is unknown, then his name probably won't be on the birth certificate. The certificate can be shown to prove that there is no other parent who has rights to the child. If the parent is dead, then a death certificate will be required.This is to prevent parents from taking the children out of the country with the intention of hiding them from the other parent. Apparently, The only way to assure that this won't happen is to get permission from both parents.
It is really a rule and as I said above, I have personally known people who have been denied boarding because of this. I have also had to deny boarding to passengers when I worked at the airport because they could not produce this information.
If the other parent says no, then theoretically the child would not be able to go.
If the other parent is unknown, then his name probably won't be on the birth certificate. The certificate can be shown to prove that there is no other parent who has rights to the child. If the parent is dead, then a death certificate will be required.
This is to prevent parents from taking the children out of the country with the intention of hiding them from the other parent. Apparently, The only way to assure that this won't happen is to get permission from both parents.