Proper Spelling

Is the spelling for this title correct? The generally excepted prinicple is that the rank or position Marshal (as in the Royal Air Force) is spelled with one "L" at the end. The spelling "Marshall" with two Ls at the end is generally a surname. Does this spelling come from any official source? Just curious. 19:40, November 30, 2013 (UTC)

It honestly might be an error on our (i..e, my) part. I'm rechecking most of the content for Pacific Rim on hand (artbook, novelization) and Pentecost's rank appears to be spelled with one "L" as opposed to two :/, Merriam-Webster dictionary lists "Marshall" as spelling variant. Lily Ford (talk) 20:10, November 30, 2013 (UTC)