I recently uploaded a few packages to CTAN, and for the license in the preamble I copied the following text from the documentation of dtxtut:
%% This file may be distributed and/or modified under the
%% conditions of the LaTeX Project Public License, either
%% version 1.3 of this license or (at your option) any later
%% version. The latest version of this license is in:
%%
%% http://www.latex-project.org/lppl.txt
%%
%% and version 1.3 or later is part of all distributions of
%% LaTeX version 2005/12/01 or later.
However the CTAN staff kindly reminded me in the emails that this is only for LPPL 1.3, not 1.3c. I then searched on the Internet, only to find the same text on the page for LPPL 1.3c.
I wonder what is the correct way to use LPPL 1.3c?
siunitx, see https://mirrors.dotsrc.org/ctan/macros/latex/contrib/siunitx/siunitx.dtx, he as far as I can see it just refers to 1.3c instead of 1.3. If you look in http://www.latex-project.org/lppl.txt it explicitly states that this is revision 1.3c, so I'm thinking that this is what the CTAN staff is refering to. – daleif Mar 11 '21 at 12:51