Immigrationboards.com

I have indefinite leave to remain and wish to apply for a UK passport for my newborn son. On the application form it asks if the parent has been granted a "certificate of registration or naturalisation". What does this mean in terms of ILR? Do I tick yes and provide the details of my biometric residence permit?

You can only apply for a British passport AFTER you register your newborn as a British Citizen first via MN1 form. You need to apply for that first given you are applying on your ILR basis.

No. If they granted a parent ILR before the child is born in the UK, then child is automatically British.

An ILR holder wasn't granted a "certificate of registration or naturalisation". Enclose proof of parent's ILR in child's British passport application.