In Conclusion

Samba ACL support is a feature that enables the manipulation of UNIX file permissions or UNIX ACLs from Windows NT/XP/2000 clients.

With this feature, almost any modification you want to make to UNIX permissions or VxFS POSIX ACLs can now be done from an NT/XP/2000 client (with the exception of the class entry for VxFS POSIX ACLs).

Windows applications running on the Windows NT/XP/2000 client cannot expect full NT/XP/2000 ACL support. Although much of the NT/XP/2000 ACL information is retained and retrieved by the Samba server, some of the information may be lost or changed in some cases.

The ACL support is not an NT/XP/2000 ACL emulation, but rather access to UNIX ACLs through the NT/XP/2000 client. Therefore you cannot run Windows applications which require full, perfect NT/XP/2000 ACL support.