samba - Jun 2002 - samba access permission questions

Hello all,

I read through the samba documentation, and tried to understand the
samba permssion setting. I had
several questions regarding to it:

[1] if set secruity = user,

Samba will use  "valid users", "invalid users" "read
list" "write list"
to validate the user connection,
and permssion. It will ignore the "username" option in the smb.conf
file. Is this right ?

[2] if set security = share

Samba will ignore the "valid users" "invalid user"
"read list" "write
list" option, and only use the
"username" to validate the user connection and permission. Is this
right
?

[3] The book "Using samba" has the following sentence: "Samba
will
attempt to validate the
  password against the list of users it has previous compile throughout
the attempted
  connections....

 How to found that list, or ask Samba to not look thougth the list.

Also, are there any FAQ regarding to Samba's security setting ? Any
comments and suggestions are appreciated. Thanks

Xiaowen,