In Djibouti I was working under the FFESSM system which IMO is a fairly radical departure from the scheme of the mainstream recreational agencies. 1* divers were not certified to dive independantly of a 'pro'. 2* was a more intense version of 'AOW' and 3-4* was very demanding. Some of the instructor ratings had me confused- to be honest I'm still a bit foggy.
I agree, the CMAS system is one of the most comprehensive training programs available. As far as the Instructor ratings are concerned, * may certify * Divers, ** Instructors may certify ** Diver, Rescue Diver, *** (Divemaster), O2, and train * Instructors (must be certified by a *** Instructor), *** Instructor (Instructor Trainer Examiner) may certify * and ** Instructors. A panel of *** Instructors appointed by the National Training Committee is required to certify a *** Instructor. Alternatively, the National Training Director may make such appointments.