Cleveland Booker IV was a courier who served as mentor to Tareckx in the 32nd century.
This Cleveland Booker was the fourth courier to operate under that name. He (and the Cleveland Bookers who preceded him) developed a reputation for trustworthiness. (DIS: "Species Ten-C")
When this Cleveland Booker retired, Tareckx adopted his name as an inspiration and motivation for himself to live up to the name. (DIS: "That Hope Is You, Part 2", "Species Ten-C")