See Copyright file in tarballs (essentially the same for both versions 0.51.1 and 6.0.0).
I believe that the following is an approximation good enough for our purposes:
myspell-ispell-GeoffKuenning (in Attic, needs to be revived, maybe renamed)
@Licenses team: myspell-ispell-GeoffKuenning is here: <http://sources.gentoo.org/cgi-bin/viewvc.cgi/gentoo-x86/licenses/myspell-ispell-GeoffKuenning?hideattic=0&revision=1.1&view=markup>
This is BSD-4 with the additional clause: "All modifications to the source code must be clearly marked as such ...", therefore I think it could go to @MISC-FREE.
(In reply to comment #0)
> myspell-ispell-GeoffKuenning (in Attic, needs to be revived, maybe renamed)
Restored from Attic, updated (clause 4 has been removed), renamed to "Ispell", and added to MISC-FREE license group.