Dimensionless experiments test the invariance of plasma physics to changes in the dimensional plasma parameters, when the canonical dimensionless parameters are conserved , . Isotope identity experiments exploit the change in isotope ion mass A = mi/mp to obtain plasmas with identical dimensionless profiles in the same tokamak. However, conditions at the plasma boundary may introduce additional physics, potentially invalidating this approach. Although the isotope mass appears explicitly only in the parameter Pi*, changing A in experiment will affect all plasma kinetic profiles, therefore achieving an isotope identity is not trivially expected a priori. The isotope identity technique  was revisited in JET-ILW with H and D plasmas, both in L-mode and type I ELMy H-modes.