File COPYING contains exactly the text of the ISC license (except for the copyright notice).
+ 28 Sep 2012; Tony Vroon <chainsaw@gentoo.org> rfkill-0.1.ebuild, + rfkill-0.2.ebuild, rfkill-0.4.ebuild: + Clarify that this is ISC-licensed, as-is is not sufficiently precise. As per + Ulrich Müller in bug #436452.