In a filing made with the Security & Exchange Commission Thursday morning, Barnes & Noble disclosed some modifications to its wide-ranging agreement with Microsoft that will give B&N the option to not develop additional Nook Window apps, but gives Microsoft the right to sell Nook content in a co-branding arrangement through the Microsoft Consumer Reader. Microsoft hasn’t confirmed what the Microsoft Consumer Reader is, but it is believed to be an e-reader app.

While B&N has already developed a Nook Windows 8 app—available in 32 countries—B&N now has the option to not create new versions for additional countries. B&N is also now allowed to stop work on a Nook Windows Phone app. If B&N chooses to stop developing additional Nook Window apps or stops development on a Windows Phone app, the revised agreement calls for B&N to “cooperate in good faith with Microsoft to transition users to the Microsoft Consumer Reader.” In the event such changes occur, the revenue sharing agreement between the two companies could be revised.

The change in language does not relieve B&N from created e-bookstores in 10 countries, something a spokesperson said B&N will accomplish by the end of April.

A spokesperson for Microsoft shed no further light on the Microsoft Consumer Reader. “We are always looking for ways to evolve and innovate on our app experiences for customers. We have nothing further to share at this time,” a statement read.