Z:gnu-www-ja-why-assign--67cdd4-=5BExplanatory note added in Jan/en

[Explanatory note added in Jan 2013: this point applies to the packages that are FSF-copyrighted. When the developers of a program make it a GNU package, they can decide either to give the copyright to the FSF so it can enforce the GPL for the package, or else to keep the copyright as well as the responsibility for enforcing the GPL. If they make it an FSF-copyrighted package, then the FSF asks for copyright assignments for further contributions, and this page explains why.]