you couldn't openly and clearly critique/satirize the whole System nor the Party nor the Leader (with all 3 being basically equivalent). You were allowed (and t

you couldn't openly and clearly critique/satirize the whole System nor the Party nor the Leader (with all 3 being basically equivalent). You were allowed (and to some degree and in some shape encouraged) to critique and have a laugh at supposedly small and separate defects/impurities on the shining body of the System, the defects which were still present as supposedly exceptions and not the rule ("otdelnye nedostatki") thus your work would supposedly be improving the System instead of weakening it. The great talent of some of those writers, directors, actors, etc. was to show those supposedly small separate defects in the formally allowed way while really making it a deep and profound satire of the whole System. The approach of course isn't unique to USSR, it has been the forced choice of artists through the history of ideological oppression in human civilization, and giving the rise of ideological intolerance everywhere today i expect to see again that approach more and more.