35 U.S.C. §26 Effect of defective execution. 
Any document to be filed in the Patent and Trademark Office and which is required by any law, rule, or other regulation to be executed in a specified manner may be provisionally accepted by the Director despite a defective execution, provided a properly executed document is submitted within such time as may be prescribed.
(Added Mar. 26, 1964, 78 Stat. 171; amended Jan. 2, 1975, 88 Stat. 1949.)