Bon nuit, mon cherie would translate as - Good night, my darling.
It is a French expression you use when you want to tell someone to sleep tight, basically.
Click on the top right of the scree it will give you options
View profile, Edit Profial, or Log out
1) Click Edit profile
2) Click <span>Preferences
</span>3) Then click "First Name"
4) Then put the name you want.
I would have to say parentheses, since its not restricted.