So on the ballot you get to list two names: your legal name and your nickname.
Another aspect of elections in Brazil is compulsory voting. In order to have your equivalent of a social security card be valid you must vote. But if you don't want to vote for anyone you can mark your ballot as "Branco" or blank.
So in the mid 90's some guy running for the legislature caused a big stink by claiming that his nickname was Branco. You can imagine the confusion this might cause.