An administrative error in the handling of The Last Guardian's trademark has forced Sony, again, to issue reassurances that the game still is in development.

Sony, to GameSpot, Videogamer.com and others, confirmed that The Last Guardian remains in development by Team Ico. It was discovered this weekend that the U.S. Patent and Trademark Office had listed Sony's trademark on The Last Guardian as abandoned because no one had answered a request to make a statement of the trademark's use or file an extension to do so.

VentureBeat noted that Sony has filed the trademark with an intent to use it, not as a trademark on an existing product. Sony was required to check in with the USPTO every six months over a span of three years, either to show it was using the trademark or make an extension. VentureBeat also noted that the Sony lawyer in charge of filing the trademark notice no longer is with the company.

The Last Guardian's development is led by Fumito Ueda, the designer behind the critically acclaimed Ico and Shadow of the Colossus. Sony has had to repeatedly deny the game's cancellation in the long span since the game's announcement at E3 2009.

At E3 2014, Shuhei Yoshida, the head of Sony's worldwide studios, reiterated that The Last Guardian was in development and, to squelch future rumors, said if the game ever was canceled Sony would make a formal announcement of that.

Update: Sony this afternoon petitioned to revive the trademark application and also requested an extension of time on its Intent to Use application, per reader and trademark attorney Patrick Soon of Newport Beach, Calif. Sony's petition to revive the trademark was accepted by the USPTO. The documents may be viewed here and here.