The policy of favouring the production and sale of books by freeing the publishers and dealers from taxes and other burdens was continued and even developed after the introduction of printing. The kings, impressed with the possibilities of this great discovery, recognised that it was for the interest of the realm to free books, printed or written, not only from _octroi_ or city duties, but from customs or importation charges. Letters-patent of Henry II., dated 1553, read as follows: _Avons ordonné et ordonnons lesdits livres, escrits ou imprimez, reliez ou non reliez, estre et demeurer exempts desdits droits de traicte foraine, Domaine forain et haut passage_.[281] This was a more liberal policy than at that time prevailed in Italy or in England, or, in fact, than has as yet been accepted in the nineteenth century by the United States. In order to obtain the advantage of such exemption, the publishers had to secure from the Rector of the university a passport or certificate for their packages. One of the earlier regulations of the university affecting the book-trade was that under which the supervision of the sale of parchment was left in the hands of the Rector. This sale was usually authorised only at the annual Lendit fair. The dealers, bringing their parchment, exposed this for inspection. Before any other purchases were permitted, the Rector selected the quantity needed for the university, for which payment was made at a price fixed in advance. He then received from the parchment-dealers, for the treasury of the university, or for the special fund of the book guild, a gratuity which amounted to from two thousand to three thousand francs.