In Belgium there is no definition in giving the secondary names of the christian names to male or female children. Sometimes you come across Josepha Maria Joseph etc.It is usely a token of respect to give the name of the grandparents. In the Middle ages is was usely the godfather and the godmothers name, when baptising the child, that was given to the child. But aristocrats and rich people started a trend by given their childern 10 or more names, in a way as a token of their respect and of their patrons protection. Lower class people followed suit.
Its the same with the titel "Madame", if you were not aristocratic you were not allowed to let someone address you with Madame. It comes from "ma dame", which is my lady. In those days you had people who worked on these complaints, they were Herauts.
When i started, it was much easier to research your ancestry. Nowadays you have to go to court to get a permission to do your ancestry when dealing with younger than 100 years. Even then it is a pain in the buth. I have reached 1600. But i am working on all todays people with the name Quackels and another one with the name Van Hoegaerden (in all its variation), its called afstammingsreeks. Older than 100 years is public domane.
In English you have an insult "son of a gun", i now were it comes from, but do you know?