Some "Star Trek" novels and comics have utilized characters that were only ever seen in the animated series, most notably Arex and M'Ress. It has been suggested by fans that these stories took place during the fourth or fifth year of Kirk's original "five-year mission." Arguably, the most-debated element of "TAS" is the introduction of Robert April as the first captain of the "Enterprise" NCC-1701. From the show's debut up until the end of the first season of "Star Trek: The Next Generation", "TAS" was considered part of "Star Trek" canon. Then, from the end of the first season of "Star Trek: The Next Generation" on May 16, 1988 (when all licenses for "Star Trek" spin-off fiction were renegotiated) up to June 27, 2007, "TAS" was "decanonized". However, on June 27, 2007, "Star Trek"s official website incorporated information from "TAS" into its library, recanonizing it.