As you probably know the chown command provides a way for the owner of a file to change the ownership of this file. In some circumstances (i.e. you want to know who created each file on your systems) you will want to avoid this behaviour.
To allow only the root user to chown, edit /etc/system and add the following:
set rstchown = 0
This will prevent users from using chown even if they were smart enough to have a copy of the /usr/bin/chown file in their own directory (i.e. to by pass changing permissions on /usr/bin/chown).