Which way to say 'private'?

[Batista, Facundo]

#- There are 2 ways to indicate private members of classes, by 
#- prepending
#- 1 or 2 underscore characters, the latter causing name mangling. My
#- question is: When would I use which kind to indicate privacy?

As a I read don't remember where, :p, to put 1 underscore is the same to
hang a "Do not disturb" sign in the door, to put 2 underscores is the same
to lock the door.

.	Facundo