You can't change over 500 years of tradition and laws.
The laws here require exact adherance to full names and correct spelling of birth names since first there are so many individuals with the same or similar names; and because of the fact that legal and financial responsibility for one's children passes back from parents to grandparents. So, in a country where you have José Felipe Silva, José Felipe da Silva, and José Felipe Silva e Costa (and probably thousands of each) you can begin to see the necessity. Also for example in a case where a couple divorces and has children where the husband is ordered to pay support for the children (Pensão Alimenticia), but skips out on it the grandparents are legally responsible and in fact can be jailed if THEY don't pay it; so there exact names are important.
Maiden (birth) names are always used when putting ancestors names on official documents here and they must appear on documents exactly the way that the appear on the original Birth Certificate of that individual, that's just the way things are done here and there is also a hierarchy of documents. For example the Birth Certificate (RG) that is superior to all other identifying documents (except for women) and it is mentioned as "Originating Document" in all other documents issued from that time forward. It will be noted as CN No. XXXXX (CN = Certidão de Nascimento and the number of one's Birth Certificate). However for women, the Marriage Certificate is superior to Birth Certificate in that it also has the power to change one's name. When a woman marries she MUST have all of her ID documents changed if she adopts her husband's name. From the time of marriage onward, she no longer uses the Birth Certificate, but rather the Marriage Certificate for purposes of ID and all future documents issued for her will mention the "Originating Document" as CC No. XXXXX (CC = Certidão de Casamento). I've never seen such a case personally, but I guess this would also be done in cases where a man were to adopt his wife's family name when he marries, which is provided for by law.
This is also the source of great legal problems for many people, both Brazilians and foreigners alike; because if the Cartórios make a simple error of spelling or anything else, one must actually go to court to obtain an Order to have that error corrected, the Cartório WILL NOT just do it on their own. So here in Brazil you see people in court all the time seeking Orders to correct the spelling mistakes in their name, or even worse still get their Birth Certificates changed to reflect the fact that they're male or female because their name induced the Escrivão (Scribe) to incorrectly record them as the wrong gender; or people seeking Orders to prove they are in fact alive because a Cartório wrongly issued a Death Certificate in their name.
While BUREAUCRACY was not invented in Brazil, the government has spent over 500 years perfecting it into an absolute science!
Cheers,
William James Woodward, EB Experts Team