Well, I am no expert. But I believe that trustee adds Access Control Lists support (ACL) to linux, thus extending the well known unix permission system (rwx). ACL is more comprehensive, flexible, powerful.
When you say syntax, I guess that you speak of the RWBEX part. You can find the answer here :
http://www.linuxsecurity.com/resource_files/host_security/trustees-quickstart.html
In short it is the ACL permissions for the share.
Please, don’t hesitate to report any findings. I have not tried anything, as I don’t have the need to turn off the public share.
