My wife and I and kids travel to Brazil about once a year. Brazil requires both parents be present while exiting the country with a child. If only one parent is traveling, he or she must have authorization from the other. Usually we have a notarized letter, but we've run into several delays (missed flights) because you never know if they will accept the letter or require a Brazilian judge's approval. What a headache! The last time it happened, my wife decided to never leave Brazil again without me. So, on our last trip, the whole family was there in RIO at the policia federal, (passport control) and the woman behind the counter began shaking her head no. I got that sinking feeling that I usually get leaving Brazil - as she called over her supervisor. It seems that my daughter's new Brazilian passport did not have the required parent association printed. (Up to this last passport, the father and mother's name were printed in the child's passport.) They informed us that the Brazilian Consulate in Atlanta who issued the passport, didn't know what they were doing and the father and mother's name must be shown in the passport. They reluctantly let us pass but warned us to travel with birth certificates as well as passports. We couldn't believe that we almost missed another flight.
When we recounted this experience with the gate agent, she told us that we were very fortunate because usually several people a day had been denied exit. Lesson Learned: We travel with all passports and birth certificates.