#t9

What does "t9" mean?
teamhybrid_95, taksolet_999999, Tuning_950, trang_92er, tamerrr_999, TOYO_965, talent_90, traykapone_9to5hustle, the10_90, tamer_999, toleen_90ali, thebloc_911, top_9111, tp_9months, tounsia_93, thewalkingdead_91, tommy_90, tamron_90mm, tens_90, tehran_95