The affidavit clause is exact and specific. It may be made either by the printer or the publisher. This exacting and drastic addition to the manufacturing clause met with strong opposition from the friends of copyright, particularly authors and book publishers, as unnecessary and unreasonable, but was successfully insisted upon by the representatives of the typographical unions. The voiding of copyright because of a false affidavit by a printer or publisher, which might even be mistakenly made and of which the author would have no cognizance, was opposed as especially unjust to authors and out of keeping with the rest of the law. Under the statute as enacted, this provision must be exactly complied with, and the courts would doubtless enforce it to the letter. {Sidenote: Importation questions} The manufacturing provision of 1891 and its extension in the code of 1909 have raised important and difficult questions as to the time at which these provisions become effective in relation with copyrights previously existing. It was claimed by Benziger Brothers, as proprietors of a copyright American edition of the "Key of Heaven," that an edition of sheets printed in America previous to the law of 1909 and sent abroad for binding, could be re-imported notwithstanding the new provision against binding, but the decision of the appraisers at New York against this claim was upheld by the Secretary of the Treasury, under advice of the Attorney-General, and the courts have not yet had occasion to pass on the question. This ruling indicates that since July 1, 1909, copyright could not be maintained on any book unless type-set, printed and bound completely within the limits of the United States, and that any copyrighted books, partly manufactured in the United States, but bound and otherwise completed abroad since July 1, 1909, must be denied importation. It has been decided, however, by the Attorney-General, that the manufacturing requirement as to binding refers only to the original, and that copyright books rebound abroad cannot be denied importation. Also it has been held that a foreign translation of a copyright work, for which translation American copyright is not claimed, cannot be refused importation. The provisions supplementing the manufacturing clause by prohibiting importation are given in the chapter on importation. {Sidenote: Foreign manufacturing provisions}