The situation can become extremely complicated if a work is distributed via multiple authorized channels, only some of which carry a notice. According to the Copyright Act of 1909, "Where the copyright proprietor has sought to comply with the provisions of this title with respect to notice, the omission by accident or mistake of the prescribed notice from a particular copy or copies shall not invalidate the copyright or prevent recovery for infringement against any person who, after actual notice of the copyright, begins an undertaking to infringe it, but shall prevent the recovery of damages against an innocent infringer who has been misled by the omission of the notice; and in a suit for infringement no permanent injunction shall be had unless the copyright proprietor shall reimburse to the innocent infringer his reasonable outlay innocently incurred if the court, in its discretion, shall so direct."[16] The 1973 Copyright Compendium explains in greater detail:[17]