Not sure that this belongs on the adoption board per se, but it is the only board that remotely aligned with my question / discussion.

My uncle went by his biological surname from birth to the age of 18. At 18 he chose to legally change his surname to that of the man who had raised him from early childhood. How do I account / record that information here on his portion of the family tree? Currently I have listed by his biological surname and his children, who were born AFTER he legally changed his surname are listed with that surname as that is what is listed on their birth certificates. Is that the correct way of handling it? Do I just make a notation, noting the circumstances behind the different names? Or . . .??