Do we add "C" to the array of licenses? What do you think? I personally think this is a viable option. As a matter of fact I would like to know if an extension is copyrighted.
Topic on Module talk:Extension
I'm not sure I understand your question. All extensions are copyrighted by someone. Software licensing is based on the copyright system. The copyright holder(s) choose a software license which describes the terms under which they allow others to use their copyrighted work.
Ah, I meant closed source software.
Self answering: Well we have "unspecified" for this. :) For the rest we would probably need a new parameter which is out of scope for this Module.