Hi Graceusa, welcome on Board.

Here is a hyphenating rule I don't quite understand. In French Québec, if a street is named after a person the name will take a hyphen if the person is dead and none if he/she is alive. Eg. René-Levesque street in Montréal is named after a former prime minister who passed away.

It is such an odd rule that most people don't even bother with the hyphens when writing out addresses.