Copyleft is a play on the word copyright and describes the practice of using copyright law to remove restrictions on distributing copies and modified versions of a work.^[7] The aim of copyleft is to use the legal framework of copyright to enable non-author parties to be able to reuse and, in many licensing schemes, modify content that is created by an author. Unlike works in the public domain, the author still maintains copyright over the material, however the author has granted a non-exclusive license to any person to distribute, and often modify, the work. Copyleft licenses require that any derivative works be distributed under the same terms, and that the original copyright notices be maintained. A symbol commonly associated with copyleft is a reversal of the copyright symbol, facing the other way; the opening of the C points left rather than right. Unlike the copyright symbol, the copyleft symbol does not have a codified meaning.^[8]