  The extremization of an appropriate entropic functional may yield to the
probability distribution functions maximizing the respective entropic
structure. This procedure is known in Statistical Mechanics and Information
Theory as Jaynes' Formalism and has been up to now a standard methodology for
deriving the aforementioned distributions. However, the results of this
formalism do not always coincide with the ones obtained following different
approaches. In this study we analyse these inconsistencies in detail and
demonstrate that Jaynes' formalism leads to correct results only for specific
entropy definitions.
