Quoting Zac's summary: "That seems like a reasonable solution. So, an ebuild can do something like LICENSE="@GPL-2+" and that will expand to whatever the definition of the GPL-2+ license group happens to be. When a new version of GPL license comes out, we simple add it to that group, and none of the corresponding ebuilds have to be updated." See URL above for related message and thread. Reproducible: Always
Alternative solution: <http://archives.gentoo.org/gentoo-dev/msg_aa67cea29aa3315a96fb2fe12a56eb78.xml>
I believe that this is obsolete, per the 20120911 council decision.