Until the time of Alexander Severus (222–235 AD), it was required that these documents be written in Latin as a marker of "Romanness" (Romanitas).
Children born illegitimately were prohibited from being registered by Augustus, although Marcus Aurelius may have removed this restriction.
Birth registrations were also used to determine if a family had at least 3 children, and was therefore eligible for privileges under the lex Papia Poppaea.
In terms of Roman law, individuals who did not register their birth were neither penalized nor disadvantaged: there are imperial rescripts (a written answer of a Roman emperor to a query or petition in writing) that state that the failure to register children should not deprive them or their right to legitimacy, and there are recorded statements of Roman Emperors Diocletian and Maximian that inform an individual that “It is a well-established rule of law that though a declaration of birth has been lost, your status is not adversely affected.” Birth registrations could be used as proof of age; however, from historical evidence, it is clear that they were not regarded as sufficient proof in themselves.
[13] For illegitimate children, the date of birth was more complex and less authoritative since it was either as originally recorded or as copied from the public register.
[15] With the initiative of the father or another close relative, standard birth registrations included the name and current age of the individual concerned and was addressed to an official.