samba - Feb 1999 - /usr/local/samba/private/MACHINE.SID

The document "Doing the NIS/NT Samba" on Linux World says that the
file
/usr/local/samba/private/MACHINE.SID should be owned by root and read-only 
for all other users.

The document "ENCRYPTION.txt" says that this directory should be owned
by
root and should have the permission 500. Therefore the file MACHINE.SID
located
in this directory will only be readable by the owner: root. Right ?

What is wrong ?