Ohio State's rigorous defense of the brand continues, this time, against the University of Oklahoma.

The university recently filed an an action against Oklahoma for its use and filed trademark of a block O logo, most prominently used on the chest of its drum major's uniform.

From NewsOK.com:

The notice of opposition was filed last week. Ohio State uses the block "O" as its primary logo, and the school extensively outlines the history of its use in the action. The University of Oklahoma Board of Regents filed a trademark application for the mark in December 2017. OU claims its block "O" has been in commercial use since 2001. The mark is most noticeable to Sooner fans as the logo on the chest of the drum major. Ohio State claims it has used the block "O" since 1898 and that Oklahoma's applied-for mark is "highly similar" and that "confusion is likely."

This is the second Big 12 school Ohio State's fought trademark battles with after Oklahoma State objected to Ohio State's attempt to trademark the acronym "OSU."

That matter was settled before it reached federal courts, but this one could prove to be the rubber match for the home-and-home football series that ended in a 1-1 draw.