Refer to the follow resources for more information.
acl man page — Description of ACLs
getfacl man page — Discusses how to get file access control lists
setfacl man page — Explains how to set file access control lists
star man page — Explains more about the star utility and its many options
http://acl.bestbits.at/ — Website for ACLs
http://www.fokus.gmd.de/research/cc/glone/employees/joerg.schilling/private/star.html — Website for the star utility