Yeah, it is defined at the bottom of the file: > A "Necessary Claim" is a claim of a patent owned by Facebook that is necessarily infringed by the Software sta

Yeah, it is defined at the bottom of the file: > A "Necessary Claim" is a claim of a patent owned by Facebook that is necessarily infringed by the Software standing alone. So when they say "license under any Necessary Claims" they are granting a patent license, the copyright license in the LICENSE file is separate. The FAQ link provided by silentstreet makes it very clear: > Does termination of the additional patent grant in the Facebook BSD+Patents license cause the copyright license to also terminate? > > No. https://code.facebook.com/pages/850928938376556 https://code.facebook.com/pages/850928938376556