All forms of intellectual property may be transferred, sold, assigned or licensed. Each form of intellectual property contains various rights, and each of those rights can be transferred alone or together. For example the author of a book can license the right to make a movie from the book, but retain all other copyrights. In addition there are certain unique considerations for each type of intellectual property. For example a trademark can only be licensed in conjunction with the transfer of certain aspects of the business to which they relate.