some only of the acts which the owner of the copyright has the exclusive right to control, or to a part only of the term of the copyright, or to a specified country or other geographical area. (3) No assignment of copyright and no exclusive licence to do an act which is subject to copyright shall have effect unless it is in writing signed by or on behalf of the assignor, the licenser or, in the case of an exclusive sublicence, the exclusive sublicenser, as the case may be. (4) A non-exclusive licence to do an act which is subject to copyright may be written or oral, or may be inferred from conduct, and may be revoked at any time: Provided that such a licence granted by contract shall not be revoked, either by the person who granted the licence or his successor in title, except as the contract may provide, or by a further contract. (5) An assignment, licence or testamentary disposition may be granted or made in respect of the copyright in a future work, or the copyright in an existing work in which copyright does not subsist but will come into being in the future, and the future copyright in any such work shall be transmissible as movable property. (6) A testamentary disposition of the material on which a work is first written or otherwise recorded shall, in the absence of a stipulation to the contrary, be taken to include the disposition of any copyright or future copyright in the work which is vested in the deceased at the time of his death. (7) A licence granted in respect of any copyright by the person who, in relation to the matters to which the licence relates, is the owner of the copyright, shall be binding upon every successor in title to his interest in the copyright, except a purchaser in good faith and without notice, actual or constructive, of the licence or a person deriving title from such a purchaser, and any reference in this Act to the doing in relation to any copyright of anything with or without the licence of the owner of the copyright shall be construed accordingly. (8) Where the doing of anything is authorized by the grantee of a licence or a person deriving title from the grantee, and it is within the terms, including any implied terms, of the licence for him to authorize it, it shall for the purpose of this Act be deemed to be done with the licence of the grantor and of every person, if any, upon whom the licence is binding. Source: http://www.wipo.int/portal/es/