When examining the NV license (specifically for xorg-x11, possibly for other packages as well) the license is not able to be found. See here for all licenses for this package: http://packages.gentoo.org/ebuilds/?xorg-x11-7.1 All other licenses work for this particular package.
I'm a little confused. The license says "as-is" and it seems to exist. Was this a problem with the ebuild that has since been fixed?
Yeah, it looks like the issue has been fixed. At some point before xorg-x11-7.1 stabilized on x86/amd64, there was a whole list of licenses. It included licenses from several companies and MIT, I think, as well as the aforementioned NV. Unless the link is found in some other package this bug should be resolved.
No more comments? Closing this bug, as it has been fixed for xorg-x11 and I haven't seen this license anywhere else.