In the anime, people who know Mr. Ral sometimes address him using Ramba Ral's rank 「大尉」 ("taii").
In the article, I say he's addressed as "Lieutenant" Ral, because that's how his rank is translated in the episodes appearing on Youtube. But when you translate military rank from Japanese to English there is some ambiguity. (Basically, 「大尉」 is like an army Captain or a navy Lieutenant.) Thus "Captain" (which appears on the Ramba Ral page) is also a valid translation.
So it's a bit of an awkward situation: Ramba Ral indicates that the character's rank is "Captain", but Mr. Ral indicates that Ral is addressed as "Lieutenant", which is Ramba Ral's rank. I don't think there's a good solution to this, except to explain the situation here. Trying to explain it in the article itself would just weigh the article down with useless data, IMO.