>>69Not much to explain. It means that if you want to submit your work into the project, you license the work so that other people can republish it without permission, so long as they attribute the author properly.
Derivative is more open-source, if you allowed derivatives, people could take your work and modify it. Very imageboard culture friendly, but maybe not good for the author. It could be optional.
Problem trying to solve: getting the work disseminated. If it can be republished without permission, its ideas can spread far and wide. This is always done informally on imageboards, but if you go outside an imageboard, its best to make it formal. If you give over the work to be published, you agree that others can republish it.
That's the suggestion as I see it.