ACLs are an addition to the standard Unix file permissions (r,w,x,-) for User, Group, and Other for read, write, execute and deny permissions. ACLs give users and administrators flexibility and direct fine-grained control over who can read, write, and execute files.
(will show file permissions)
#setfacl -m u:user:rw- filename
(Gives user read,write permission over filename
show files which have acces control lists applied ("+" sign in last collumn)