The role of constraints in Tsallis' nonextensive treatment revisited

We revisit the nonextensive treatment advanced by Tsallis, et al. (Physica A 261 (1998) 534) in order to perform a rather exhaustive study of its properties and compare them with the earlier formalism devised by Curado and Tsallis (J. Phys. A 24 (1991) L69). Some interesting features are in this way revealed.