According the Fusible, a website that keeps track of domain names, Warner Bros. has secretly registered several domain names for possible titles of the "Man of Steel" sequel. Right now the movie has been given the unofficial title "Batman vs. Superman."

The studio has not released an official name for the sequel which has left many fans guessing and speculating about the title could be. According to Fusible, Warner Bros. registered the names through MarkMonitor, an Internet based protection company. The registered names (and possible titles) are below:

"Man of Steel Battle the Knight"

"Man of Steel Beyond Darkness"

"Man of Steel Black of Knight"

"Man of Steel Darkness Falls"

"Man of Steel knight Falls"

"Man of Steel Shadow of the Night"

"Man of Steel The Blackest Hour"

"Man of Steel The Darkness Within"

Warner Bros. also reportedly registered shorter versions of the names like "Battle the Knight," "Beyond Darkness," "Black of Knight," etc. It also should be noted that MarkMonitor is the same company the studio used to register its own and the domain.

Of course this is all speculation. Warner Bros. has not responded to the rumors and according to several reports the studio won't release an official name for another couple months.

According to Latino-Review, a fan-favorite name has been "World's Finest."

"@elmayimbe World's Finest is perfect. Doesn't need Supes or Bats in title any more than Avengers needed Iron Man in there. People get it," @mmarkmillar tweeted.

"Just call it 'Superman & Batman' followed by whatever subtitle you want. Worlds Finest will do. Why turn this into a branding nightmare," @chrisbrandt posted.

"The possible titles WB is thinking about for the Batman VS Superman movie are horrible. 'World's Finest' = there ya go. Simple," @tommyglynnfw tweeted.

However other people felt naming the sequel "World's Finest" would be too vague and leave some people confused.

"If I saw a movie called 'World's Finest' I would have 0 clue it was Superman/Batman," @youthinkmemad commented.

What do you think the "Man of Steel" sequel should be called?