Keith Bowden writes…
I'm hoping you might have a minute to address this in your blog. It's been observed that the poster, etc., credits have been revealed for the upcoming Warner Bros. feature Batman v Superman and though Wonder Woman is in the movie, William Moulton Marston is not credited alongside Bob Kane and Siegel & Shuster. Gal Gadot, the actress portraying her, appears in the credits. I'm sure Marston will be listed in the end credits crawl, but why isn't he in the main credits? What are the WGA rules on such things?
The Writers Guild has nothing to do with that. They only determine and have rules about credits for those who actually write on a movie or TV show. The "created by" credits on Superman, Batman, Wonder Woman (etc.) are all contractual matters between DC Comics and the parties credited.
Incidentally — because I've been asked about this — the Writers Guild determines screen credits based on actual written material. Every so often, I hear or read an interview with someone who had verbal input (they claim) into a movie or a TV show based on a comic book and they say, "I was promised a writing credit." No one can promise you a writing credit when multiple writers are involved because the WGA has final say on that. And Sam Shmidlap is not going to even be eligible for a writing credit unless the credit arbitrators can read a treatment or script that was committed to paper and which says "Written by Sam Shmidlap" on it. Beware of those who claim they wrote a movie or TV show but have no paper to show for it. (And of course, even paper may not prove they wrote enough of it to earn a credit.)