Assignment documents and cover sheets, or copies of the same, which are returned by Assignment Division will be stamped with the original date of receipt by the Office and will be accompanied by a letter which will indicate that if the returned papers are corrected and resubmitted to the Office within the time specified in the letter, the Office will consider the original date of receipt of the papers as the date of recording of the document. See 37 CFR 3.51. The certification procedure under 37 CFR 1.8 (see MPEP § 512) or the “Priority Mail Express®” procedure under 37 CFR 1.10 (see MPEP § 513) may be used for resubmissions of returned papers to obtain the benefit of the date of deposit in the United States Postal Service to establish that the papers were returned within the time period specified. If the returned papers are not corrected and resubmitted within the specified period, the date of receipt of the corrected papers will be considered to be the date of recording of the document. The specified period to resubmit the returned papers will not be extended.