Complex sentence: In addition, legal rights can only be signed away if local law admits it; so a properly signed paper contract may not be enough to abrogate copy owners rights, unless there are special legal provisions admitting it.
Split into simpler sentences: In addition, legal rights can only be signed away if applicable law permits it. So even a properly signed paper contract may not be enough to abrogate copy owners rights, unless there are special legal provisions admitting it.