(1) A person entitled to a right conferred under this Part may waive the right or consent to the doing of any act in relation to the work in respect of which the right subsists and any act done under such waiver or consent is not an infringement of the right.
(2) A right may be waived by instrument in writing signed by the person giving up the right and the waiver—
(a) may relate to works generally or to a specific work or class of works and may relate to existing or future works; and
(b) may be conditional or unconditional and may be expressed to be subject to revocation.
(3) Where a waiver is made in favour of the owner or prospective owner of the copyright in the work or works to which it relates, it shall be presumed to extend to his or her licensees and successors in title.
(4) Nothing in this Part shall be construed as excluding the operation of the general law of contract or estoppel in relation to an informal waiver or other transaction in relation to any of the rights to which this Part relates.