is there a way of telling if your adopted by looking at your birth certificate?

I have quite a few friends that are adopted and there is one way you can tell. Look at the date of birth and then look at the date the birth certificate was signed. Adoptions take a bit to be finalized so it would be off. A regular birth certificate is signed one to two days after birth. An amended birth certificate is signed months after the date of birth. That's really the only way to tell and it's not common knowledge. I personally hate amended birth certificates. It doesn't make any sense. While the adoptive parents are parents, they did not give birth and that's all a birth certificate is, a record of birth. If anyone else falsified into like that on a legal document, they would go to jail.

My daughters BC is not a different color. There is no way by looking at her BC to find out that she is adopted. She knew from early on.

I never heard of it and it would depend on the laws of the land where the child is adopted, so even anyone knows I would be interested in knowing too.