Using Samba: A File and Print Server for Linux, Unix & Mac OS X, 3rd Edition
| directory security mask = value |
Allowable values : octal value from 0 to 0777
Default : same as directory mode
Controls which permission bits can be changed if a user edits the Unix permissions of directories on the Samba server from a Windows system. Any bit that is set in the mask can be changed by the user; any bit that is clear remains the same on the directory even if the user tries to change it. Requires nt acl support = YES .