stˈɑːɹɾɪŋ wɪððə tˈiː twˈɛnti, ðɪ ˈɔːɹdnəns dᵻpˈɑːɹtmənt ɪnˈɪʃəli dɪvˈɛləpt θɹˈiː sˈɪɹiz ʌv ɪmpɹˈuːvd mˈiːdiəm tˈæŋk pɹˈoʊɾoʊtˌaɪps, ðə tˈiː twˈɛnti, tˈiː twˈɛnti tˈuː, ænd tˈiː twˈɛnti θɹˈiː.
Starting with the T20, the Ordnance Department initially developed three series of improved medium tank prototypes, the T20, T22, and T23.