The Star Trek canon is the set of all canonical material in the Star Trek universe. The official Star Trek website defines canon as comprising the television series and feature films of the franchise. Television series As a rule, all Star Trek television series that aired are considered part of the canon. This policy does not make clear which version of the series is the canonical one. For example, the remastered episodes of the original series, released in 2006, present several visual differences from the episodes originally aired. Roddenberry's impact Gene Roddenberry was something of a revisionist when it came to canonicity. People who worked with Roddenberry remember that he used to handle canonicity, not on a series-by-series basis nor an episode-by-episode basis, but point by point. If he changed his mind on something, or if a fact in one episode contradicted what he considered to be a more important fact in another episode, he had no problem declaring that specific point not canonical. Additionally, David Gerrold, in an interview about Star Trek: The Animated Series, commented on Roddenberry's parsimony and how it originally affected the Star Treks canon: From non-canon to canon Occasionally, writers will draw from non-canonical works in creating new canon. Such is the case of the first names for Hikaru Sulu and Nyota Uhura, which were first used in the novel The Entropy Effect and the reference book Star Trek II Biographies, respectively. Several concepts that first appeared in The Animated Series, which was considered to be non-canonical for several decades (1980s–2000s), were used in other Star Trek productions during that time. Kirk's middle name, first used in the episode "Bem" before it was used in Star Trek VI: The Undiscovered Country. (Gene Roddenberry wrote the novelisation of Star Trek: The Motion Picture and confirmed the middle name, Tiberius, in the Foreword.) The animated episode "Yesteryear" first introduced The Forge and the city of ShiKahr, which were later included in the Enterprise three-part story that started with "The Forge". Unreadable text One final issue comes from text that appears on props such as computer displays, but is not legible during the episode, except in modern HDTV broadcasts. The transcript of the text can often be obtained through behind-the-scenes pictures and interviews. This leads to the question of whether material that is in the episodes but cannot be seen clearly should be considered canon. Often, this material