seems fairly straight forward, a note added to the birth registration/registry

Another option

If the child is 18 years or over and applies for a copy of their birth certificate, they receive an addendum attached to the certificate advising that there is additional information about their birth record.

http://www.qld.gov.au/law/births-deaths-marriages-and-divorc...


MAKING AMENDMENTS, CORRECTIONS AND/OR ADDENDA TO CIVIL ACTS

• A person on whose name a relevant civil act is registered may apply for amendment or/and addenda to a record in a civil act;
• A parent/adopter may apply for amendment or/and addenda to a record in a civil act of child/adoptee in that part of the record which concerns parent/adopter;
• A parent, adopter, guardian or carer may apply for amendment or/and addenda to a record in a civil act registered on the name of a minor under 18 years of age and incapable person;
• Any interested person may apply for amendment or/and addenda to a record in a civil act of a deceased person.

http://sda.gov.ge/en/Other-Services/#amendments


(a) The state registrar may attach to the original record an addendum that sets out any information received by the state registrar that may contradict the information in a birth, death, or fetal death record required to be maintained in the bureau of vital statistics.

(b) If the state registrar attaches an addendum to an original record, the state registrar shall instruct the local registration official in whose jurisdiction the birth, death, or fetal death occurred to attach an identical addendum to any duplicate of the record in the official's custody.

http://codes.lp.findlaw.com/txstatutes/HS/3/191/B/191.033#st...