37 CFR 1.471 - Corrections and amendments during international processing.
(a) Except as otherwise provided in this paragraph, all corrections submitted to the United States Receiving Office or United States International Searching Authority must be in English, in the form of replacement sheets in compliance with PCT Rules 10 and 11, and accompanied by a letter that draws attention to the differences between the replaced sheets and the replacement sheets. Replacement sheets are not required for the deletion of lines of text, the correction of simple typographical errors, and one addition or change of not more than five words per sheet. These changes may be stated in a letter and, if appropriate, the United States Receiving Office will make the deletion or transfer the correction to the international application, provided that such corrections do not adversely affect the clarity and direct reproducibility of the application (PCT Rule 26.4). Amendments that do not comply with PCT Rules 10 and 11.1 to 11.13 may not be entered.