Results of ion cyclotron resonance heating (ICRH) of deuterium-tritium (D-T) divertor plasmas of JET in ITER-relevant scenarios and in ITER-like configuration are presented. H-mode experiments have been performed in D-T plasmas with up to 95% of tritium in scenarios such as the second harmonic heating of tritium (2wCT), (D)-minority heating in T (wCD) and He3-minority in DT mixtures. Relevant to the initial non-active campaign of ITER, 'inverted' minority schemes (Z/M of the minority species being higher than that of the majority) such as He3 and D-minority in H plasmas including T-minority in D plasmas have also been studied in L-mode. In the latter schemes requiring operation at lower frequencies, the coupled power capability is lower (see below) and the H-mode threshold power is higher. Operation in such a variety of scenarios has been possible in JET due to the existence of a very wide frequency range (23-56 MHz) of the ICRH plant. For an operation of the JET tokamak with a toroidal field on-axis of 3.4-3.7 T, the above scenarios, for example, required operation at 23, 28, 34, 42, 51 and 56 MHz. The JET ICRH system couples power via four antennas distributed around the torus. Antennas are equipped with Faraday shields made out of beryllium. Each antenna has four straps which can be phased independently. Up to 9 MW of ICRH power has been coupled in single-null DT divertor H-mode plasmas.