Concepts of 'reversible wholly plastic deformation (as in cleavage)' and 'elastic equilibrium stretching' are widely used for derivation of the generalized Lippmann equations for surface tension of solid electrodes. Here we show that the first one (reversible wholly plastic deformation') is an idealized concept having no relation with real plastic deformation of metals by irreversible dislocation movement. 'Plastic deformation by cleavage' is a case of mixed notions since cleavage is not a kind of deformation; it is a kind of irreversible fracture without the steps of plasticity. So the thermodynamic equations based on these misleading concepts cannot be correct. (c) 2006 Published by Elsevier B.V.