Re: Um... Some help
You don't. All characters in the game are publicly listed in the Cast.
However, if you want to keep secrets you can simply not publish a description (store it at the bottom of your character sheet until you're ready to publish), so all the players can see is a name.
Or, if even the name is too much, create characters called NPC1, NPC2, etc, put their real name inside the character sheet, and then change the name and publish a description when you're ready.
Hope that helps.