This license was found in texlive-texmf, in texmf/tex/generic/hyphen/hyphen.tex.
The FSF's rationale regarding the LaTeX Project Public License 1.2 applies to this specific scenario: http://www.fsf.org/licensing/licenses/index_html#GPLIncompatibleLicenses
This license contains complex and annoying restrictions on how to publish a modified version, including one requirement that falls just barely on the good side of the line of what is acceptable: that any modified file must have a new name.
The reason this requirement is acceptable for LaTeX is that TeX has a facility to allow you to map file names, to specify “use file bar when file foo is requested”. With this facility, the requirement is merely annoying; without the facility, the same requirement would be a serious obstacle, and we would have to conclude it makes the program non-free.
Thus, this license is free but GPL incompatible, but only on TeX files. If this license were applied to unrelated code, it would almost certainly be non-free due to the renaming restriction.
% The Plain TeX hyphenation tables [NOT TO BE CHANGED IN ANY WAY!] % Unlimited copying and redistribution of this file are permitted as long % as this file is not modified. Modifications are permitted, but only if % the resulting file is not named hyphen.tex.
%%% license = "Unlimited copying and redistribution of this file %%% are permitted as long as this file is not %%% modified. Modifications, and distribution of %%% modified versions, are permitted, but only if %%% the resulting file is renamed.",