This parameter controls what UNIX permission bits can be modified when a Windows NT client is manipulating the UNIX permission on a directory using the native NT security dialog box. This parameter is applied as a mask (OR'ed with) to the changed permission bits, thus forcing any bits in this mask that the user may have modified to be on. Make sure not to mix up this parameter with , which works in a similar manner to this one, but uses a logical AND instead of an OR. Essentially, this mask may be treated as a set of bits that, when modifying security on a directory, to will enable (1) any flags that are off (0) but which the mask has set to on (1). If not set explicitly this parameter is 0000, which allows a user to modify all the user/group/world permissions on a directory without restrictions. Users who can access the Samba server through other means can easily bypass this restriction, so it is primarily useful for standalone "appliance" systems. Administrators of most normal systems will probably want to leave it set as 0000. 0 700 directory security mask security mask force security mode