The re-centring capability is, among the four main functions of seismic isolation systems, the one least kept in due consideration by designers. This has led, in certain cases of earthquake attack, to serious damage and even structural collapse in the wake of excessive cumulative displacements. This author developed a theoretical approach to this main function, suggesting an energy-based criterion for its quantification and the newly proposed criterion was accepted for an oral presentation at the 13th WCEE (Vancouver, 2004). Its experimental validation occurred within the framework of the LESSLOSS Research Project funded by the European Commission and has been adopted in the European Norm EN 15129 : Anti-seismic Devices. The scope of the paper is that of illustrating the state-of-the-art in the framework of re-centring capability evaluation and confront the problems involved, comparing the requirements specified in the different standards, as well as commenting on the blatant discrepancies thereof.