https://github.com/mquinson/po4a/blob/master/README.md specifies that "This program is free software; you may redistribute it and/or modify it under the terms of GPL (see COPYING file).". Since there is no "or later" or "(at your option) any later version"-statement, the LICENSE should be specified as GPL-2 instead of GPL-2+. Nevertheless there are some files in /usr/lib64/perl5/vendor_perl/5.36/Locale/Po4a which are licensed as GPL-2+ which are installed by the ebuild. So the ebuild should use LICENSE="GPL-2 GPL-2+". Reproducible: Always
https://github.com/mquinson/po4a/blob/master/COPYING is the license file and it says GPL-2+.